This treatment differs from Flora of Thailand: Mallotus kingii, M. penangensis, M. stipularis, and M. subpeltatus are transferred to Hancea, and former Trewia nudiflora is included in Mallotus. Mallotus actinoneurus is a new record, M. tokiae a new species.

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Genus description

Identification key

Species descriptions

Key to the species of Macaranga, Mallotus, and Trewia

Lour., Fl. Cochinch.: 635. 1790; Pax & K.Hoffm. in Engl., Pflanzenr. VI.147.vii: 145. 1914; Airy Shaw, Kew Bull. 26: 292. 1972; Whitmore, Tree Fl. Mal. 2: 113. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 160. 1975; G.L.Webster, Ann. Missouri Bot. Gard. 81: 89. 1994; Bollendorff et al., Blumea 45: 319. 2000; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 93. 2000; Slik & Welzen, Blumea 46: 3. 2001; Radcl.-Sm., Gen. Euphorbiacearum: 225. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 384. 2007; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 126, Fig. 28. 2014.— Echinus Lour., Fl. Cochinch.: 633. 1790.— Trewia L., Sp. Pl.: 1193. 1753 (‘Trevia’); Müll.Arg. in DC., Prodr. 15, 2: 953. 1866; Hook.f., Fl. Br. Ind. 5: 423. 1887; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 140. 1914; Gagnep. in Lecomte, Fl. Indo-Chine 5: 343. 1925; Airy Shaw, Kew Bull. 20: 405. 1967; Kew Bull. 26: 343. 1972; Whitmore, Tree Fl. Mal. 2: 134. 1973; G.L.Webster, Ann. Missouri Bot. Gard. 81: 90. 1994; Kiu et al., Fl. Sin. 44: 11. 1996; Philcox in Dassan., Fl. Ceylon 2: 142. 1997; Susila & Balakr., J. Econ. Tax. Bot. 22: 345. 1998; Govaerts et al., World Checkl. Bibl. Euphorb. 4: 1560. 2000; Radcl.-Sm., Gen. Euphorb.: 231. 2001; Kulju, Welzen & Nanakorn in Welzen & Chayam., Fl. Thailand 8, 2: 568. 2007.— Rottlera Roxb., Pl. Corom. 2: 36. 1798 (non Willd., 1797).— Canschi Adans., Fam. Pl. 2 (1763) 443, nom. superfl.— Rottlera Willd., Gött. J. Naturwiss. 1 (1798) 7 (non 1806).— Adisca Blume, Bijdr.: 609. 1826.— Lasipania Raf., Sylva Tellur.: 21. 1838.— Plagianthera Rchb.f. & Zoll., Verh. Natuurk. Ver. Ned. Indië 1: 19. 1856.— Hancea Seem., Bot. Voy. Herald: 409. 1857.— Axenfeldia Baill., Étude Gén. Euphorb.: 419. 1858.— Coelodiscus Baill., Étude Gén. Euphorb.: 293. 1858.— Aconceveibum Miq., Fl. Ind. Bat. 1: 389. 1859.— Echinocroton F.Muell., Fragm. Phytogeogr. Austral. 1: 31. 1859.— Diplochlamys Müll.Arg., Flora 47: 539. 1864.

Shrubs to trees (climbers), usually dioecious; flowering branches usually flattened. Indumentum usually of simple and stellate hairs, whitish to reddish glandular scales. Stipules caducous. Leaves alternate to opposite, one of each pair smaller; petiole usually hardly pulvinate at both ends; blade usually papery, symmetric, margin usually denticulate, upper surface usually with black to brown extrafloral nectaries, lower surface with glandular scales and often domatia in nerve axils; venation penninerved to palmate. Inflorescences terminal to axillary (to ramiflorous), usually single, unbranched (thyrsoid) racemes; flowers with abscission zone in pedicel, sepals 3–6, petals and disc absent. Staminate flowers usually in groups per node; sepals free, often spreading or reflexed; stamens 15–250, thecae often separated by broad connective, latter often with apical clumps of cells; pistillode lacking (except for M. glomerulatus). Pistillate flowers single (or 2) per node; sepals usually persistent; ovary usually 3-locular, often echinate; 1 ovule per locule; style usually present, persistent; stigmas undivided, usually with long, slender, branching papillae, persistent. Fruits lobed capsules to indhescent drupes, often armed with spines; column usually slender, apically broadening. Seeds usually naked, or with an aril, especially when young.

    A paleotropical genus with 150 species ranging from Africa and Madagascar through S. and S.E. Asia, Malesia to Australia and the W. Pacific; in Thailand 39 species of which three are new records and one newly described. Classification: Subfamily Acalyphoideae, tribe Acalypheae, subtribe Rottlerinae. The Thai species are divided over eight sections: Axenfeldia (opposite, penninerved leaves), Hancea (opposite, penninerved leaves, one reduced to a bract), Mallotus (alternate, triplinerved or palmate leaves, echinate capsules, 45–100 stamens), Oliganthae (alternate, triplinerved leaves, reduced inflorescences, no glandular scales), Polyadenii (penninerved leaves with adaxial glandular scales), Rottlera (alternate leaves, unarmed fruits), Rottleropsis (opposite, triplinerved leaves), and Stylanthus (alternate to opposite, triplinerved to peltate leaves, armed capsules, 15–45 stamens, coumarin/fenucreek smell). In the near future the species in the sections Hancea and Oliganthae will be transferred to the genus Cordemoya. This genus is new to Thailand. The transfer is a result of molecular and micromorphological research. The species in Cordemoya lack extrafloral nectaries, glandular scales, and stellate hairs, but have glandular hairs.

Key to the species

1. Mallotus actinoneurus Airy Shaw , Kew Bull. 33: 63. 1978; S.E.C.Sierra et al., Blumea 52: 46, map 1. 2007. 

Shrubs, 1.5–3 m high, dioecious. Indumentum composed of simple, tufted and stellatelytufted hairs, glandular scale hairs absent. Stipules narrowly triangular, 8.2–13 by 2.5–3.5 mm, persistent, margin entire, apex acute, densely to sparsely hairy, especially outside. Leaves opposite to rarely alternate; petiole 1.4–6.3 cm long, densely hairy, basal and apical pulvinus hardly broadened; blade elliptic to obovate, 25–35 by 7–14 cm, length/width ratio 2.1–3.6, chartaceous, base shallowly and narrowly emarginate, margin entire to denticulate with a few subapical glandular teeth, apex caudate, upper surface sparsely hairy on midrib and nerves, larger extrafloral nectaries marginal in lower half, 3 or 4 per side, 1–4 mm from margin, elliptic to orbicular, 0.7–0.8 by 0.7–0.8 mm, smaller ones all over the blade, 0.2–0.3 by 0.2–0.3 mm, lower surface sparsely hairy except for the densely hairy midrib, domatia absent, venation pinnate, nerves 9 or 10 per side, looping and closed near margin. Staminate inflorescences axillary racemes, 1 or 2 per node, reduced in length, up to 2 cm long, 1 or 2 flowers per node, basally a dense group of bracts; basal bracts linear, c. 5.5 by 0.8 mm, upper bracts linear, c. 3 by 0.3 mm, accompanied by 2 slightly smaller bracteoles, all outside hairy, inside (sub)glabrous. Staminate buds slightly ellipsoid, c. 2 mm in diam.; pedicel c. 1.8 mm long, thickening towards apex, densely hairy; sepals still too young to open, densely hairy outside; stamens many, probably c. 50. Infructescences racemes, with a single terminal fruit, c. 1.7 cm long, erect, single; peduncle c. 2 mm long; bracts linear-triangular, 3.5–7 by 0.7–1 mm, margin entire or trilobed, apex acute, densely hairy; bracteoles absent. Pistillate flowers (based on young fruit) c. 10 mm diam.; pedicels c. 2.5 mm long, densely hairy; sepals 3, triangular to narrowly triangular, 8–10 by c. 3 mm, free, margin entire, apex acute; ovary c. 9 by 8 mm, 3-locular, densely hairy; style c. 2.2 mm long; stigmas c. 6 by 1–1.2 mm. Fruits capsules, 15–18 by 23–27 mm, opening septicidally-loculicidally, surface smooth, densely hairy; wall 1.8–2 mm thick, glabrous inside; column c. 11.5 by 11.5 mm. Seeds ± globose, c. 12 by 11.5 by 12 mm, surface rugose, dull, light brown.

    T h a i l a n d.— PENINSULAR: Narathiwat (Klong Ai Ka Pa in Hala-Bala Wildlife Sanctuary: POOPATH, THANAROS, WEECHEANCHAN & INSURA 76, BKF).

    D i s t r i b u t i o n.— Endemic in the eastern border area of Thailand and the Malay Peninsula (Type).

    E c o l o g y.— In tropical rain forest and logged areas, in shade, by stream. Altitude: 50—80 m. Flowering: August; fruiting: April.

2. Mallotus barbatus Müll.Arg., Linnaea 34: 184. 1865; Hook.f., Fl. Brit. Ind. 5: 418. 1887; Gagnep. in Fl. Gén. I.-C. 5: 357, fig. 1, map 1. 1925; Airy Shaw, Kew Bull. 26: 296. 1972; Whitmore, Tree Fl. Mal. 2: 113. 1973; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 97. 2000; S.E.C.Sierra & Welzen, Blumea 50: 251. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 389, Fig. 21, Plate XXI: 1. 2007. — Rottlera barbata Wall., Cat.: no. 7822. 1847, nom. nud. — Mallotus esquirolii H.Lév., Feddes Repert. 9: 461. 11 Aug. 1911, nom. inval., non Mallotus esquirolii H.Lév., 10 May 1911 (= M. khasianus). — Mallotus leveilleanus Fedde, Feddes Repert. 10: 144 (’léveillanus’). 1911. — Mallotus leveillei Fedde ex H.Lév., Fl. Kouy-Tcheou: 165. 1914, nom. superfl. — Mallotus barbatus Müll.Arg. var. congestus F.P.Metcalf, Lingnan Sci. J. 10: 487 (‘congesta’). 1931. —Mallotus barbatus Müll.Arg. var. pedicellaris Croizat, J. Arnold Arbor. 19: 135. 1938. — Mallotus conspurcatus Croizat, J. Arnold Arbor. 21: 501. 1940. — Mallotus croizatianus F.P.Metcalf, J. Arnold Arbor. 22: 204. 1941. — Mallotus lotingensis F.P.Metcalf, J. Arnold Arbor. 22: 206. 1941. — Mallotus luchenensis F.P.Metcalf, J. Arnold Arbor. 22: 206. 1941. — Mallotus barbatus Müll.Arg. var. hubeiensis S.M.Hwang, Acta Phytotax. Sin. 23: 296. 1985. — Mallotus barbatus Müll.Arg. var. croizatianus (F.P.Metcalf) S.M.Hwang, Acta Phytotax. Sin. 23: 295. 1985. —Mallotus barbatus Müll.Arg. var. wui H.S.Kiu in Chang & Kiu, Guihaia 23: 99. 2003.

Shrubs to trees, up to 10 m high. Indumentum densely stellately, patently hairy, floccose, gladular scales whitish to orangish. Stipules linear triangular, 6–10 by 0.5–1 mm. Leaves alternate (some opposite beneath inflorescence); petiole 3.2–19.5 cm long; blade ovate, widest in lower third, 11–37 by 8.5–30 cm, length/width ratio 1.1–1.2, drying brownish, base peltate by 18–60 mm, round, margin glandularly denticulate, sometimes lobed, longest lobes up to 45 mm, apex acuminate to cuspidate, upper surface subglabrous, with up to 4 black extrafloral nectaries below insertion, c. 1.5 by 1 mm, lower surface densely hairy on venation, with glandular scales, venation palmate. Inflorescences terminal, often branching. Staminate inflorescence erect, up to 29 cm long, side branches up to 10.5 cm long, flowers in groups of 3 per node; bracts triangular, c. 4 by 0.8 mm. Staminate flowers 7.5–8.5 mm in diameter; pedicel 3.6–5.5 mm long, sepals 4 or 5, ovate to elliptic, 3.5–5 by 1.2–3 mm, pale light cream to tan-cream; stamens more than 50, filaments 2–3.7 mm long, pale light green to yellow, anthers c. 0.4 mm long, pale light yellow. Pistillate inflorescences becoming pendent, up to 41 cm long, side branches up to 16 cm long; bracts triangular, 4.5–10 by 0.8–1.9 mm; bracteoles 2.7–4 mm long. Pistillate flowers 4–6 mm in diameter, yellowish red; pedicel 1.5–4(–9 in fruit) mm long; calyx with 4(5) lobes, 3.3–5 mm high, lobes ovate, 2.1–2.8 by 2–2.8 mm; ovary (3)4(5)-locular, 2–2.5 by 2–3 mm; style 0.5–1.5 mm long; stigmas 4.5–6 mm long. Fruits lobed capsules, 18–21 by 16–19 mm, yellow to ligh brown, uniformly, densely covered with layer of up to 5 mm long spines, latter densely stellately hairy; column 6–9 mm long. Seeds obovoid, 5–5.5 by 3.5–4 by 3.5–4 mm.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Chiang Dao, Doi Saket), Chiang Rai (Chiang Kum, Kua Katan, Kuhn Jae, Nam Mae Kok), Phayao (Doi Luang), Nan (Doi Tiew, Nuang Pua), Lampang (Chae Son), Phrae (Ban Ko), Phitsanulok (Tung Salaeng Luang); NORTH-EASTERN: Phetchabun (Loam Kao, Nam Nao, Phu Miang), Loei (Nam Nao), Nong Khai (Bungkla), Sakon Nakhon, Nakhon Phanom (Phu Langka), Khon Kaen (Chum Phae); EASTERN: Chaiyaphum (Ban Nam Phrom); SOUTH-WESTERN: Uthai Thani (Nong Chang), Kanchanaburi (Huai Bahn Goa), Phetchaburi (Kaeng Krajan); SOUTH-EASTERN: Chanthaburi (Makham); PENINSULAR: Chumphon, Surat Thani (Bang Yai), Trang (Thung Khai).

    D i s t r i b u t i o n.— India (syntypes), Myanmar, China, Thailand, Indochina, and the Malay Peninsula (Singapore: syntype).

    E c o l o g y.— Pioneer species in open, often very disturbed or burned places in mainly deciduous forest, also in mixed evergreen forest, hill dipterocarp forest, and in light thickets along paths; soil: at base of limestone, bedrock shale or sandstone. Altitude: 140–1000 m.

    V e r n a c u l a r.— Khi thao (ขี้เท่า), Tao khon (เต๊าขน), Tong tao (ตองเต๊า), Po tao (ปอเต๊า) (Northern); Ya khi thut (หญ้าขี้ทูต) (Sakon Nakhon); Hu chang (หูช้าง) (Phetchabun); Po hun (ปอหุน) (Prachuap Khiri Khan); Salapang (สละป้าง), Salapang bai yai (สละป้างใบใหญ่) (Chanthaburi); Krarok khon (กระรอกขน) (Chumphon); Kalo khon (กะลอขน), Kalo yai thai (กะลอยายทาย) (Peninsular); Ba-le-a-nging (บาเละอางิง) (Malay-Narathiwat); Siamese pom-pom tree (English).

    N o t e.— See note under Mallotus tetracoccus.

3. Mallotus brevipetiolatus Gage, Rec. Bot. Surv. Ind. 9: 242. 1922; Airy Shaw, Kew Bull. 21: 393. 1968; Kew Bull. 26: 293. 1972; Whitmore, Tree Fl. Mal. 2: 115. 1973; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 97. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 391, Fig. 22. 2007.

Shrubs to trees, up to 8 m tall. Indumentum mainly absent, few simple and stellate hairs, few orangish glandular scales. Stipules elliptic, 2.7–6 by 1.6–4 mm. Leaves opposite; petiole 2–4 mm long; blades ellipticly obovate, 4.5–21.5 by 2–8 cm, length/width ratio 2.3–2.7, drying brownish, base very narrowly cordate, margin laxly shallowly crenulate to denticulate with glands in dentations or teeth, apex bluntly acuminate, upper surface glabrous, 1 or 2 (to several) narrowly elliptic extrafloral nectaries subbasally besides midrib, lower surface (sub)glabrous, few glandular scales, no domatia, venation penninerved, distinct on both sides. Inflorescences terminal (to axillary), single, unbranched. Staminate inflorescences up to 14 cm long; flowers in groups of up to 7 per node; bracts ovate, c. 1.2 by 1.2–1.3 mm. Staminate flowers 3.5–4.3 mm in diameter, (light yellow) green to white, scented; pedicel c. 2 mm long; sepals 4, elliptic-obovate, 2.3–2.5 by 1.2–1.3 mm; stamens 30–35, filaments 1–2.3 mm long; anthers 0.4–0.6 mm long. Pistillate inflorescences up to 6 cm long; bracts triangular, c. 1.3 by 1 mm. Pistillate flowers 5.5–7.5 mm in diameter; pedicel 2(–6 in fruit) mm long; sepals 5, triangular, 1.2–4.3 by 0.9–4 mm; ovary 3-locular, 1.7–2.8 by 2.5–3.8 mm, spines few, in groups, round, thick, up to 1.2 mm long; style 0.9–1.5 mm long; stigmas 3–3.5 mm long. Fruits lobed capsules, 5.8–8.9 by 9–13 mm, greenish to yellowish green, glabrous, covered with glandular scales, slightly armed with few broken off spines, up to 0.6 mm long; column c. 4.5 mm long. Seeds subglobose, c. 6.5 by 6.5 by 5.7 mm.

    T h a i l a n d.— SOUTH-EASTERN: Chanthaburi (Soid Dao Ma, Tha Mai); PENINSULAR: Surat Thani (Nong Wai), Phangnga (Tumnamput), Trang (Palien), Songkhla (Khao Rup Chang).

    D i s t r i b u t i o n.— Thailand, N. Peninsular Malaysia (syntypes).

    E c o l o g y.— Shaded area in secondary to evergreen forest on limestone. 10–200 m.

    V e r n a c u l a r.— Po hun kan san (ปอหุ้นก้านสั้น) (Central).

4. Mallotus calocarpus Airy Shaw, Kew Bull. 21: 395. 1968; Kew Bull. 26: 294. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 98. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 391, 2007.

Shrubs to small trees, up to 5 m high. Indumentum of stellate and simple hairs, few whitish glandular scales. Stipules triangular, 4.5–9 by 1–3 mm. Leaves opposite; petiole 0.4–3.1 cm long; blade elliptic, 6.5–29.7 by 2.1–10.5 cm, length/width ratio 2–3.1, drying greenish, base attenuate, margin (entire to) dentate, apex bluntly acuminate, upper surface only hairy on midrib, basally with 3–5 pairs of brown extrafloral nectaries, up to 2 by 1 mm, in a row, ending just above the first distinct pair of nerves, lower surface hairy, with a few glandular scales near the base, nerve axils with small pockets; venation penninerved. Inflorescences terminal or axillary, single, not branching. Staminate inflorescences up to 1.5 cm long, with groups of up to 3 flowers; bracts triangular, 3.2–4.2 by 1.5–1.8 mm. Staminate flowers c. 4 mm in diameter; pedicel c. 3 mm long; sepals 3, elliptic, 2.7–3.3 by 1.6–2.2 mm, light green to white; stamens 30–60, filaments c. 2.8 mm long, white, anthers c. 0.7 mm long, yellow. Pistillate inflorescences reduced to a terminal single or two flowers, next to each other; bracts triangular, 3.3–6.2 by 1.2–1.8 mm; bracteoles triangular, c. 1.1 by 0.9 mm. Pistillate flowers c. 6 mm in diameter, brown; pedicel 0.7(–6 in fruit) mm long; sepals 5 or 6, ovate to triangular, 2.2–6 by 1–2.2 mm; ovary 3- or 4-locular, style c. 3.3 mm long, stigmas 3.5–4 mm long. Fruits lobed capsules, c. 21 by 15 mm, densely stellately villose, not armed; column c. 8 mm long. Seeds subglobose, 8.5–9 by c. 8 by 7–7.5 mm, greyish.

    T h a i l a n d.— SOUTH-EASTERN: Chanthaburi (Grating Falls, Khao Sabap, Khao Kitchakut, Plieuw Waterfall, Prew Agricultural Station).

    D i s t r i b u t i o n.— Endemic in Thailand (type: Khao Sabap, Chanthaburi, KERR 17965, holo in K, iso in BK).

    E c o l o g y.— Scattered along stream in open area, secondary forest, seasonal rain forest or evergreen forest. Altitude: 135–300 m.

5. Mallotus coudercii (Gagnep.) Airy Shaw, Kew Bull. 20: 42. 1966; Kew Bull. 21: 381. 1968; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 393. 2007.— Coelodiscus coudercii Gagnep., Notul. Syst. (Paris) 4: 49. 1923.— Coelodiscus glabriusculus auct. non Kurz: Gagnep. in Lecomte, Fl. Indo-Chine 5: 372. 1925.— Mallotus spodocarpus Airy Shaw, Kew Bull. 21: 383. 1968; Kew Bull. 26: 304. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 109. 2000.

Shrublets up to 50 cm high. Indumentum of sparse, long simple and stellate hairs, glandular scales whitish. Stipules triangular, 2.3–7 by 0.6–1 mm. Leaves opposite; petiole 0.3–5.5 cm long; blade elliptic, 2.2–16 by 1.2–8 cm, length/width ratio 1.8–2, drying brownish, base broadly shallowly emarginate to truncate, margin subentire to denticulate with glandular teeth, apex rounded to bluntly acuminate, upper surface glabrous to some hairs on especially midrib, no extrafloral nectaries, lower surface subglabrous to somewhat hairy on venation, usually hair tuft domatia, glandular scales sparse, venation triplinerved. Inflorescences mainly axillary, very short, single, not branching. Staminate inflorescences up to 2 cm long, usually dichasial and forming large clumps of flowers, flowers c. 5 per node; bracts elliptic, 1.6–2.3 by 0.4–0.7 mm. Staminate flowers: pedicel 1–2 mm long; sepals 3–5, elliptic to obovate, c. 4 mm long; stamens c. 25, filaments still young. Pistillate inflorescences usually reduced to (1)2(–4)-flowered spikes, up to 2 cm long; bracts c. 3 by 0.7 mm. Pistillate flowers c. 3.3 mm in diameter; pedicel 1(–4.5 in fruit) mm long; sepals 3 or 4, ovate, c. 3.3 by 1.1 mm; ovary 3-locular, c. 2 by 2.7 mm, not armed, densely villose; style 0.9–1 mm long; stigmas 1.7–2 mm long. Fruits lobed capsules, 10–12 by 7–8 mm, unarmed, densely villose; column not seen. Seeds subglobose, 5–6 mm in diameter.

    T h a i l a n d.— NORTHERN: Nakhon Sawan (Hua Wai); EASTERN: Nakhon Ratchasima; SOUTH-WESTERN: Kanchanaburi (Ta Salao, Wang Kanai), Phetchaburi (Ko Yoi); CENTRAL: Chai Nat, Saraburi (Menam Sak, Saraburi).

    D i s t r i b u t i o n.— Thailand (type: Hua Wai, Nakhon Sawan, PUT 2169, holo in K, iso in BK), Vietnam (Annam).

    E c o l o g y.— Along sunny waysides, in mixed forest, deciduous forest, bamboo forest; soil reported a few times as limestone. Altitude: 20–250 m.

    V e r n a c u l a r.— Ta khe khum wang (ตะเข้คุมวัง) (Phetchaburi); Tao tua mia (เต่าตัวเมีย) (Chai Nat).

6. Mallotus decipiens Müll.Arg., Linnaea 34: 194. 1865; Hook.f., Fl. Brit. Ind. 5: 434. 1887; Airy Shaw, Kew Bull. 26: 303. 1972; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 394. 2007. — Coelodiscus eriocarpoides Kurz [J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 42, 2: 244. 1873] Forest Fl. Brit. Burma 2: 392. 1877.— Mallotus cuneatus Ridl., J. Roy. As. Soc. Str. Br. 59: 181. 1911; Airy Shaw, Kew Bull. 21: 389. 1968; Kew Bull. 26: 294. 1972; Whitmore, Fl. Mal. Pen. 2: 115. 1973.— Coelodiscus muricatus auct. non (Wight) Gagnep.: Gagnep. in Lecomte, Fl. Indo-Chine 5:369, p.p. 1925.— Mallotus resinosus (Blanco) Merr. var. cuneatus  (Ridl.) N.P.Balakr. & Chakrab., Rheedea 1: 39. 1991.— Mallotus resinosus auct. non (Blanco) Merr.: Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 107. 2000

Shrubs to trees, up to 5 m high. Indumentum of simple hairs, (some) stellate hairs, glandular scales whitish to orangish. Stipules triangular, 3.2–6.3 by 1.4–2 mm. Leaves opposite; petiole 0.2–2.6 cm long; blade obovate (to smaller ones sometimes elliptic), 2.4–25.5 by 1.2–13.2 cm, length/width ratio 1.9–2, drying greenish, base rounded to narrowly emarginate, margin glandularly dentate, apex acuminate to caudate, upper surface glabrous to hairy on sunken midrib, basally usually at least with 2 relative large extrafloral nectaries on basal nerves, up to 5 per leaf side, up to 1 by 0.5 mm, lower surface glabrous to hairy on venation, with glandular scales, venation triplinerved. Inflorescences axillary to terminal, single, not branching. Staminate inflorescences erect, up to 11 cm long; flowers in groups of 3(–6) per node; bracts ovate, c. 2 by 0.9 mm. Staminate flowers c. 4 mm in diameter, light green to yellow; pedicel 1.5–5 mm long; sepals 3 or 4, elliptic, 1.7–2 by 1–1.2 mm; stamens 25–45, filaments 1.5–2.1 mm long, light greenish-whtitish, anthers 0.2–0.3 mm long, cream. Pistillate inflorescences up to 12 cm long; bracts ovate to triangular, c. 1.3 by 0.6–1 mm. Pistillate flowers 3–3.3 mm in diameter, dark white; pedicel 0.5(–8 in fruit) mm long, ovary 3(4)-locular, 1–1.1 by 1–1.7 mm, green; style 0.3–0.8 mm long, yellow-green; stigmas 1.3–2.3 mm long, yellow-green. Fruits lobed capsules, 6–7 by c. 3 mm, green with reddish tinge, somewhat echinate with up to 0.8 mm long, blunt spines; column 2.7–3.2 mm long. Seeds subglobose, 3–4.5 by 2.8–4 by 2.8–4 mm.

    T h a i l a n d.— NORTHERN: Chiang Mai, Tak, Lampang; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Kanchanaburi, Ratchaburi, Phetchaburi, Prachuap Khiri Khan; CENTRAL: Saraburi, Nakhon Nayok; SOUTH-EASTERN: Sa Kaeo, Prachin Buri, Chon Buri, Chanthaburi; PENINSULAR: Chumphon, Surat Thani, Phangnga, Phatthalung, Trang.

    D i s t r i b u t i o n.— S. India, Ceylon, Andaman & Nicobar islands, Myanmar, Thailand, Indochina, Malay Peninsula (?), Java, Philippines (type), Sulawesi, Lesser Sunda Islands, New Guinea, N. Queensland.

    E c o l o g y.— In (dry) evergreen forest, deciduous forest, disturbed forest with much bamboo, in clearings, along streams; soil: mainly on limestone, also on shale. Altitude: 20–1525 m.

7. Mallotus dispar (Blume) Müll.Arg., Linnaea 34: 191. 1865; in DC., Prodr. 15, 2: 971. 1866 (excl. var. psiloneurus Müll.Arg. = M. resinosus); Airy Shaw, Kew Bull. 21: 380, 1968; Kew Bull. 26: 303. 1972; Whitmore, Tree Fl. Mal. 2: 115. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 169. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 99. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 394. 2007.— Rottlera dispar Blume, Bijdr.: 608. 1825.— Mallotus dispar (Blume) Müll.Arg. var. lasioneurus  Müll.Arg. , Linnaea 34: 191. 1865, nom. inval.— Coelodiscus dispar (Blume) Kurz, J. Asiat. Soc. Bengal 42, 2: 244. 1873, nom. nov., nom. inval.

Shrubs to small trees, up to 10 m high. Indumentum of stellate and simple hairs, villose, yellowish to reddish glandular scales. Stipules triangular, very large, 5–6 by 1.2-1.5 mm. Leaves opposite; petiole 4-5 cm long (absent in reduced leaf); blade elliptic to obovate, 5-20 by 4-9 cm, length/width ratio 1.3-2.2, drying greenish, base rounded to cuneate, not peltate to subpeltate for 1 mm, margin glandularly denticulate, apex acuminate to cuspidate, upper surface glabrous except for midrib and major nerves, with 1 or 2 basal large extrafloral nectaries per side, elliptic to orbicular, 0.5-2 by 0.5-1 mm, lower surface sparsely hairy, with small pockets in nerve axils; venation triplinerved. Inflorescences axillary to terminal, single, not branching, flowers yellow, scented. Staminate inflorescences up to 12 cm long, green; flowers in groups of up to 5 per node, bracts trilobed (to seldom divided into bract and 2 bracteoles), 3–8.2 by 2–3 mm. Staminate flowers 2.2–4.2 mm in diameter; pedicel 1.9–3 mm long, sepals 3 (4), elliptic to obovate, 1.8–2.2 by 0.5–1.3 mm; stamens 37–50, filaments 1.7–2.7 mm long, anthers c. 0.25 mm long; pistillode present. Pistillate inflorescences up to 12 cm long; bracts trilobed, 3.5-6 by 0.8–1.7 mm. Pistillate flowers c. 6.5 mm in diameter; pedicel up to 2(–8.5 in fruit) mm long; sepals 3-5, triangular to ovate, 3-4 by 0.8–1.2 mm; ovary 3-locular, 1.8-2 by 1.8-2 mm (spines not measured), armed; style 0.7-1 mm long; stigmas 3-4 mm long. Fruits lobed capsules, 8-12 by 9.5-13 mm, dull greenish when unripe, armed with 60-80, up to 6 mm long, round, slender spines, covered with simple hairs; column 3-5 mm long. Seeds subglobular, 4-5 by 4-5 by 4-5 mm, shiny, without aril.

    T h a i l a n d.— PENINSULAR: Songkhla (Boripath Waterfall), Narathiwat (Bacho).

    D i s t r i b u t i o n.— Thailand, Indochina, Malay Peninsula, Sumatra, and Java (type).

    E c o l o g y.— Mainly in shaded places in primary evergreen forest, also along streams, sea shore and in waste places; always limestone bedrock. Altitude: 0–250 m.

8. Mallotus floribundus (Blume) Müll.Arg., Linnaea 34: 187. 1865; Hook.f., Fl. Brit. Ind. 5: 432. 1887; Airy Shaw, Kew Bull. 26: 306. 1972; Whitmore, Tree Fl. Mal. 2: 113. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 172. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 99. 2000; Slik & Welzen, Blumea 46: 33, fig. 13, map 3. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 395. 2007.— Adisca floribunda Blume, Bijdr.: 610. 1825.— Rottlera floribunda (Blume) Hassk., Cat. Hort. Bog.: 238. 1844.— Mappa floribunda (Blume) Zoll. & Moritzi, Syst. Verz.: 17. 1855.— Mallotus amentiformis Müll.Arg., Flora 42: 468. 1864.— Mallotus anamiticus Kuntze, Rev. Gen. Pl. 2: 608. 1891.— Coelodiscus anamiticus (Kuntze) Gagnep. in Lecomte, Fl. Indo-Chine 5: 375. 1925.— Mallotus floribundus (Blume) Müll.Arg. var. pilosus Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 174. 1914.

Shrubs to trees, up to 12 m tall, smelling of fenugreek. Indumentum of simple, a few stellate, and many glandular scales. Stipules ovate, 2.5–3.5 by c. 1.2 mm. Leaves alternate to subopposite; petiole 3.3–11.7 cm long; blade ovate, 7–19 by 5–14.5 cm, length/width ratio 1.3–1.4, drying brownish, base rounded, peltate by 1–2 cm, margin subentire with a few glandular teeth and often shallow undulations, apex acuminate, usually mucronulate, upper surface glabrous, with (0–)2–4 small extrafloral nectaries in a row in peltate part, round, 0.3–0.5 mm in diameter, lower surface with few hairs, many glandular scales, pockets with hair tufts in especially basal nerve axils, glaucous, venation palmate. Inflorescences terminal to axillary, single or 2 together, unbranched; bracts broadly ovate, 3–3.2 by 2.5–3.5 mm; flowers scented; bracts (broadly) ovate, 0.6–2.6 by 0.5–2.8 mm. Staminate inflorescences up to 20 cm long; flowers in groups of up to 6 per node. Staminate flowers c. 3.5 mm in diameter, white; pedicel c. 2.3 mm long; sepals 3, ovate, c. 3.2 by 2 mm; stamens c. 70, filaments c. 2.3 mm long, anthers c. 0.3 mm long. Pistillate inflorescences up to 14 cm long. Pistillate flowers greenish to yellow; pedicel 0–2.5 mm long in fruit; sepals 3, ovate, 3.3–4 by 1.8–2.2 mm; ovary 3-locular, c. 1.4 by 1.4 mm (without spines), spines up to 2 mm long; style 1.5–2.5 mm long; stigmas 7–8 mm long. Fruits lobed capsules, c. 15 by 9 mm, green to yellow-green, with red glandular scales, armed with caducous round, slender, hairy spines, up to 3 mm long; column c. 6 mm long. Seeds subglobular, 5–7 by 5–7 by 4–6 mm.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Huoy Tap Sakal); PENINSULAR: Ranong (Kraburi), Surat Thani (Khao Tum, Khlong Saeng, Wang Sai), Phangnga (Bangto), Krabi (Nai Sa), Nakhon Si Thammarat (Chong, Groong Ching Falls, Ron Pi Bul), Trang (Khao Chang), Pattani (To Mo), Narathiwat (Waeng).

    D i s t r i b u t i o n.— Myanmar, Thailand, Laos, Vietnam, throughout Malesia (Java: type) up to the Solomon Islands.

    E c o l o g y.— By streams in evergreen forest; limestone bedrock. Altitude: 40–300 m.

    V e r n a c u l a r.— Lo (ล้อ), Pik (ปิก), Prik (ปริก) (Nakhon Si Thammarat, Prachuap Khiri Khan); Lo khon (ลอขน) (Trang); Ka-bing ba-tu (กาบิงบาตู) (Malay-Narathiwat); Blue blade (English).

    U s e s.— Ornamental in Myanmar. The aromatic staminate flowers are used for scenting medicinal powders and for toilet powder on Java. A decoction of the root is administered in the Malay Peninsula after childbirth, for stomach ache and cholera. On Sumatra the tough wood is used to make small objects.

9. Mallotus garrettii Airy Shaw, Kew Bull. 21: 387. 1968; Kew Bull. 26: 306. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 100. 2000; Slik & Welzen, Blumea 46: 36, fig. 14, map 5. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 397. 2007.

Shrubs to trees, up to 9 m high, smelling of fenucreek. Indumentum of few simple and stellate hairs, mainly on inflorescences, white to yellow-orange glandular scales. Stipules triangular, 1.5–1.9 by 0.8–0.9 mm. Leaves opposite to alternate, terminally grouped; petiole 1.2–8.5 cm long; blade ovate, 5–18 by 2.4–9 cm, length/width ratio 1.3–3.3, drying brownish, base truncate to rounded, not to slightly pulvinate by 2 mm, margin subentire, with few glandular teeth, apex acuminate to cuspidate, upper surface glabrous, 0–4 basal extrafloral nectaries on nerves or veins, 0.6–1.3 by 0.5–0.7 mm, apically sometimes 1–5 extrafloral nectaries, lower surface (sub)glabrous except for many glandular scales, venation triplinerved to palmate. Inflorescences terminal to axillary, single (to grouped), unbranched. Staminate inflorescences up to 13 cm long; flowers in groups of up to 8 per node; bracts broadly ovate, c. 0.7 by 0.6–1.1 mm. Staminate flowers: pedicel 2–3.3 mm long; sepals 3, ovate to elliptic, 2.3–2.8 by 1.5–1.7 mm; stamens 30–45, filaments c. 2 mm long; anthers c. 0.4 mm long. Pistillate inflorescences up to 11 cm long; bracts ovate, c. 1 by 0.2–1 mm; bracteoles absent. Pistillate flowers: pedicel 2(–3.5 in fruit) mm long; sepals 2–5, ovate, 2–3 by 0.6–2 mm; ovary 3-locular, echinate, spines 2.2–3 mm long, densely stellate, numerous glandular scales; style 1–2.5 mm long; stigmas c. 5 mm long. Fruits lobed capsules, 8–11 by 6–8 mm, greyish-light greenish, glandular scales present, hairy, echinate, spines c. 3 mm long. Seed immature, 6–7 mm long.

    T h a i l a n d.— NORTHERN: Phayao (Doi Luang National Park), Nan (Doi Pha Ngua).

    D i s t r i b u t i o n.— Thailand (type: Doi Pha Ngua, Nan, GARRETT 140, holo in K, iso in L) and Laos.

    E c o l o g y.— Shaded rocky stream area in mixed, primary evergreen and deciduous forest; shale bedrock. Altitude: 650–1600 m.

10. Mallotus glabriusculus (Kurz) Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 162. 1914; Airy Shaw, Kew Bull. 26: 303. 1972; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 396, Plate XX: 3. 2007. — Coelodiscus glabriusculus Kurz, Forest Fl. Brit. Burma 2: 393. 1877. — Mallotus clellandii Hook.f., Fl. Brit. Ind. 5: 435. 1887; Airy Shaw, Kew Bull. 21: 381. 1968; Kew Bull. 26: 302. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 98. 2000. — Mallotus tristis Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 154. 1914.

Shrubs, up to 2 m high. Indumentum often sparse, simple and stellate hairs, whitish glandular scales. Stipules triangular, 3.2–3.8 by 0.3–0.8 mm. Leaves opposite; petiole 0.7–4.5 cm long; blade ovate (to elliptic), 7.6–20.5 by 2.6–8.7 cm, length/width ratio 1.8–2.9, drying brownish, base narrowly emarginate, margin subentire (to denticulate), with glandular teeth; apex bluntly acuminate to cuspidate, often mucronulate, upper surface glabrous except for midrib, basally 1 (or 2) pairs of extrafloral nectaries, 0.3–0.6 mm in diameter, often on one side an additional 1 or 2 somewhat higher; lower surface subglabrous to hairy on venation, with hair tuft domatia, venation triplinerved. Inflorescences terminal, single, not branching. Staminate inflorescences racemes, up to 2.2 cm long; flowers in groups of up to 4 per node, very tight together; bracts triangular, 2.4–2.8 by 0.8–1 mm. Staminate flowers c. 7 mm in diameter, yellowish; pedicel c. 2 mm long; sepals 3, ovate, 4–4.7 by 2–3.3 mm; stamens c. 60, filaments 1.3–2.3 mm long; anthers c. 0.7 mm long. Pistillate inflorescences umbels with up to at least 4 flowers; bracts stipule-like, 1.7–3 by c. 1 mm. Pistillate flowers c. 9 mm in diameter; pedicel 2.5(–24 in fruit) mm long, green; sepals 3, ovate, 5–5.2 by 1.2–1.7 mm; ovary 3-locular, c. 2 by 2.8 mm, short blunt spines up to 0.4 mm long; style c. 1 mm long; stigmas c. 3.5 mm long. Fruits lobed capsules, c. 12 by 9 mm, reddish green, spines not very dense, very narrow, up to 1.5 mm long; column c. 5 mm long. Seeds subovoid, c. 6.8 by 5 by 4.9 mm.

    T h a i l a n d.— NORTHERN: Lampang (Mae Long, Mae Wang); NORTH-EASTERN: Udon Thani (Nong Bua); EASTERN: Ubon Ratchathani (Phu Chong Na-Yoi).

    D i s t r i b u t i o n.— Myanmar, Thailand, Indochina.

    E c o l o g y.— Mixed deciduous forest, mixed dry dipterocarp forest; soil: sandy. Altitude: 100–500 m.

    V e r n a c u l a r.— Kok kradum (กกกระดุม) (Eastern).

11. Mallotus glomerulatus Welzen in Welzen, R.W.Ham & Kulju, Thai For. Bull. 32: 174, fig. 1, 2; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 397, Fig. 23, Plate XXI: 2. 2007.

Shrub, 1-1.5 m high, monoecious, but sexes at least on separate branches; young branches shortly hairy, glabrescent. Indumentum mainly of white stellate hairs and a few simple ones; glandular scales absent. Stipules triangular, 3–4 by 1–2 mm. Leaves opposite, distichous; petiole 6–15 mm long, completely pulvinate, pilose; blades of each pair usually equal, elliptic, 9.3–25.5 by 2.5–8.2 cm; length/width ratio 3–3.8, drying greenish, base attenuate, margin entire except for a single subapical tooth at each side, apex acuminate, glabrous, upper surface with round (small ones) to elliptic (larger ones) extrafloral nectaries, basal ones twice as large as smaller ones, latter in loops of nerves along margin; vernation penninerved. Inflorescences single, ramiflorous to terminal, very shortly peduncled, peduncle c. 7 mm long; with glomerules of flowers, either with many staminate flowers or a single to a few (c. 4) pistillate flowers; bracts single per flower, triangular, c. 2 by 1–2 mm. Staminate flowers c. 3.7 mm in diameter, white-green; pedicel c. 4 mm long; sepals 3, ovate, 3.3–3.5 by 1–1.2 mm; stamens c. 26, filaments c. 1 mm long, anthers c. 1.2 by 0.4 mm; pistillode a short stalk, c. 0.3 mm long, with a few hairs on top. Pistillate flowers c. 4 mm in diameter, (sub)sessile when young, white; calyx 4-lobed, c. 4.5 mm deep, lobes c. 3 by 1.7 mm; ovary 3(4)-locular, c. 2 by 1.8 mm, villous, without spines; style c. 2.3 mm long, hairy, stigmas c. 4 mm long. Fruits lobed capsules, on a short (3–4 mm long) pedicel, c. 14 by 10 mm, with few hairs outside, glabrescent, wall thin, rather woody; column broadly T-shaped, 7.5–8 mm long. Seeds obovoid, 7.7–8 by 6.2–7 by 5.5–6 mm, covered by a thin sarcotesta (when young?).

    T h a i l a n d.— NORTH-EASTERN: Nakhon Phanom (Phu Langka National Park).

    D i s t r i b u t i o n.— Endemic in northeastern Thailand (type: Nakhon Phanom Prov., Ban Phaeng District, Phu Langka National Park, Tat Pho waterfall, KOONKHUNTHOD, SUPUNTEE & THETSNA 524, holo in L, iso in BKF)..

    E c o l o g y.— Scattered in dry evergreen forest; shaded. Altitude: 150–200 m. Flowering: May; fruiting: August.

    V e r n a c u l a r.— Mak lium (หมากเหลี่ยม).

12. Mallotus hispidospinosus Welzen & Chayam., Kew Bull. 56(3): 650. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 399, Fig. 24. 2007. — Mallotus sp. nov. 1: Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 108. 2000.

Small shrubs. Indumentum dense, simple hairs (sometimes few more or less stellately together), few whitish glandular scales. Stipules needle-like, triangular, 3–6.2 by 0.4–0.5 mm. Leaves opposite; petiole 0.1–2 cm long; blade ovate, 4.8–18.5 by 1.3–7.1 cm, length/width ratio 2.6–3.7, drying brownish to greenish, base emarginate, margin glandularly dentate, apex caudate, mucronulate, upper surface glabrous, no extrafloral nectaries; lower surface hairy on venation, few glandular scales basally, venation penninerved. Staminate inflorescences and staminate flowers not seen. Pistillate inflorescences terminal, 1–3 together, 1- or 2-flowered each, up to 3.5 cm long; bracts ovate to triangular, 2.3–3 by 0.7–1 mm. Pistillate flowers yellow; pedicel 1(–7.5 in fruit) mm long; sepals 4, ovate, 4.5–5 by 1.2–1.4 mm; ovary 3-locular, c. 2 by 2.2, densely set with setose spines; style less than 1 mm long; stigmas c. 7 mm long. Fruits lobed capsules, still young, up to 1.7 cm in diameter (including spines), green, very densely set with up to 2.2 mm long, thin, strap-like spines with patent, stiff hairs; column c. 4.5 mm long. Seeds not seen.

    T h a i l a n d.— SOUTH-WESTERN: Kanchanaburi (Huai E-tawng, Pilok, Sangkhla Buri).

    D i s t r i b u t i o n.— Endemic in Thailand (type: Pilok, Kanchanaburi, PRAYAD SANGKHACHAND 821, holo in BK), perhaps also in Myanmar.

    E c o l o g y.— Hill top, evergreen forest. Altitude: 1100 m.

    N o t e.— The staminate flowers are missing and, therefore, it is dubious whether this is a Mallotus or a Macaranga, because both have the same type of spines on the fruit in some species (e.g., Mallotus glabriusculus and Macaranga trichocarpa, respectively). The number of thecae of the stamens is decisive for the genus. Moreover, real stellate hairs are lacking (typical for Mallotus, though exceptions exist). However, the needle-like stipules, opposite leaves and short inflorescences are all reminiscent of Mallotus.

13. Mallotus hymenophyllus Airy Shaw, Kew Bull. 21: 381. 1968; Kew Bull. 26: 303. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 100. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 399. 2007.

Shrubs up to 1 m tall, monoecious. Indumentum of simple hairs and few translucent, yellow glandular scales only. Stipules triangular, 2–3 by c. 0.7 mm. Leaves opposite; petiole 2.2–12 cm long; blade ovate, 4.8–31 by 5–21 cm, length/width ratio 1–1.5, drying greenish, base cordate, margin glandularly denticulate or crenulate, apex acuminate, upper surface mainly glabrous, with 1–3 pairs of extrafloral nectaries on the palmate nerves near insertion, lower surface glabrescent, often with pockets or hair tufts in axils of nerves and veins, glandular scales along base, venation palmate. Inflorescences terminal to axillary, single (to 3 together), not branched. Staminate inflorescences up to 16 cm long; flowers in groups of up to 11; bracts triangular, 0.9–2 by 1.1–1.5 mm. Staminate flowers c. 5 mm in diameter, white; pedicel up to 12 mm long; sepals 3, elliptic, 3.3–3.4 by 1.3–2.7 mm, green; stamens c. 50, filaments c. 1.5 mm long, white to yellow, anthers 0.6–0.7 mm long, light yellow. Pistillate inflorescences up to 14 cm long; bracts ovate, c. 2 by 1 mm. Pistillate flowers c. 5 mm in diameter; pedicel 4.5–5 mm long; sepals 5 or 6, elliptic, 2.2–2.7 by c. 1 mm, green; ovary 3-locular, c. 3 by 1.5 mm including densely set spines, spines with few hairs; style c. 1.7 mm long, light greenish; stigmas c. 4.2 mm long, light greenish. Fruits lobed capsules, c. 11 by 7 mm, turning maroon, sparsely covered with papillae-like, up to 2 mm long spines; column c. 5 mm long. Seeds globose, c. 6 mm in diameter.

    T h a i l a n d.— PENINSULAR: Surat Thani (Ban Tahmnieb, Khao Sok, Kiensa, Panom, Song Pi Nong), Krabi (Ao Luk, Tarn Bok Khorani Arboretum).

    D i s t r i b u t i o n.— Endemic in Thailand (type: Sawng Pi Nawng, Surat Thani, KERR 12389, holo in K, iso in BK).

    E c o l o g y.— Evergreen forest, bamboo forest to in shaded, overgrown places in Hevea rubber plantation, often cut back; soil: limestone bedrock. Altitude: 20–100 m.

14. Mallotus khasianus Hook.f., Fl. Brit. Ind. 5: 438. 1887; Airy Shaw, Kew Bull. 21: 396. 1968 (typification); Kew Bull. 26: 294. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 100. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 401. 2007.— Mallotus filiformis Hook.f., Fl. Brit. Ind. 5: 435. 1887.— Mallotus. polyneurus Hook.f., Fl. Brit. Ind. 5: 439. 1887.— Mallotus esquirolii H.Lév., Feddes Repert. 9: 327. 10 May 1911, non M. esquirolii H.Lév., 11 Aug. 1911 (= M. barbatus).

Deciduous to evergreen shrubs to trees, up to 14 m high. Indumentum of simple and stellate hairs, orangish (to whitish) glandular scales. Stipules triangular, usually groups together at beginning of branches, 2–3.2 by 1–1.7 mm. Leaves opposite; petiole 0.2–8 cm long; blade ovate to elliptic (to slightly obovate), 3.2–24.5 by 1.5–11 cm, length/width ratio 1.7–2.3, usually drying brownish, base narrowly emarginate to (broadly) cuneate, margin dentate to seemingly subentire, with glandular teeth, apex cuspidate to caudate, upper surface glabrous, (with none to) subbasally, submarginally 2 pairs of round extrafloral nectaries, 0.3–0.5 mm in diameter, lower surface (sub)glabrous, with glandular scales, pockets in nerve axils, usually with hair tufts, venation penninerved. Inflorescences terminally to ramiflorous, pendulous, single (to occasionally two together), not branched. Staminate inflorescences up to 43 cm long; flowers in groups of up to 7 per node; bracts triangular, 1.7–2.2 by 1.4–2.2 mm. Staminate flowers 5.7–8 mm in diameter, pale-yellow, slightly fragrant; pedicel 6.2–7 mm long; sepals 4, elliptic, 3.2–4 by 1.9–2.7 mm; stamens 35–45, filaments 2.2–2.8 mm long, cream, stamens 0.5–0.7 mm long, cream. Pistillate inflorescences up to 28 cm long; bracts triangular 1–2 by 1–1.7 mm. Pistillate flowers 8–15 mm in diameter (including stigmas), reddish green; pedicel 4(–15 in fruit) mm long; sepals usually 6, ovate, 3–3.8(–6) by 0.9–1.8 mm, light yellow-green; ovary 3-locular, c. 1.8 by 2 mm, light yellow-green, armed with up to 3.5 mm long spines; style 1.3–3 mm long; stigmas 9–13 mm long. Fruits lobed capsules, c. 18 by 10 mm, greenish brown, hairy, with glandular scales, sparsely armed (breaking off), with mainly apically hairy spines; column c. 8.5 mm long. Seeds subellipsoid, 10–11 by 8–9.5 by 8–9 mm.  

    T h a i l a n d.— NORTHERN: Mae Hong Son (Doi Chong), Chiang Mai (Chomthong, Doi Angka, Doi Inthanon, Doi Lohn, Doi Nang Ka, Doi Suthep, Khun Kong San, Mae Kang), Nan (Doi Phukha), Lampang (Chae Son), Phitsanulok (Phuhin Rongkla), Kamphaeng Phet (Mae Wong); NORTH-EASTERN: Loei (Phu Kradueng); SOUTH-WESTERN: Kanchanaburi (Khao Ri Yai).

    D i s t r i b u t i o n.— India (Assam, type), Myanmar, and Thailand.

    E c o l o g y.— Usually very common in the understorey of deciduous and hill evergreen forest, also in partly open places and sunny road sides, often along streams; soil: granite bedrock. Altitude: 650–2100 m.

    V e r n a c u l a r.— Ngao nok (เงานก), Ngao-pa (เงาป่า), Sipo (สีป้อ), Sipo yang (สีป้อยาง) (Northern).

15. Mallotus kongkandae Welzen & Phattar., Blumea 67: 46. 2001; S.E.C.Sierra, Welzen & Slik, Blumea 50: 224, fig. 1, map 1. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 402, Fig. 25, Plate XXII: 1. 2007. — Mallotus philippensis (Lam.) Müll.Arg. var. mengliangensis C.Y.Wu ex S.M.Hwang, Acta Phytotax. Sin. 23: 294. 1985.

Tree, c. 8 m high; flowering twigs 2–3 mm thick, young parts tomentose. Indumentum tomentose on most parts when young, consisting of simple and stellate hairs and glandular scales. Stipules triangular, c. 1.5 by 0.6 mm, tomentose outside, glabrous inside. Leaves alternate with tendency to terminal groups on the branches, simple; petiole terete, 1.5–5 cm long, somewhat pulvinate at both ends, with longitudinal ridges when dry, tomentose when young; blade ovate, 8–18 by 3.4–5.5 cm, length/width ratio 2.4–3.3, chartaceous, symmetric, drying greenish, base rounded, margin entire and seemingly glandless (only older leaves seen), apex gradually acute to acuminate, mucronulate, upper surface glabrous except for the basal part of the midrib, basally with 2, black, extrafloral nectaries near petiole attachment, c. 1 by 0.7 mm in size; lower surface tomentose, white, glandular scales many, domatia absent; venation penninerved, triplinerved, slightly raised above, raised underneath, nerves 10–12 per side, marginally looped and closed, veins scalariform, veinlets densely reticulate. Staminate inflorescences and flowers unknown. Infructescences terminal, single, not branching, 3.5–8 cm long, tomentose; bracts and bracteoles triangular, tomentose outside, glabrous inside, bracts c. 1 by 0.8 mm, bracteoles c. 0.5 by 0.5 mm. Pedicels 2.5–3 mm long, terete, tomentose, subbasally with abscission zone. Fruits capsular, subglobose (slightly flattened dorsoventrally), not lobed, 12–14 by c. 11 mm, not armed, with dense covering of orange (green when dry) glandular scales, somewhat ribbed and pustular when dry, dehiscing loculicidally and tardily, partly septicidally; wall thick, c. 2 mm in middle to 3 mm apically; column c. 6 mm long, apically broadened and T-shaped, caducous. Seeds ± ovoid but somewhat flattened and with central ridge on axillary side, c. 5 by 4.2 by 3.5 mm, single per locule, dark brown, naked.

    T h a i l a n d.— NORTHERN: Chiang Rai (Doi Tung), Kamphaeng Phet (Mae Wong National Park).

   D i s t r i b u t i o n.— China (Yunnan), Thailand (type: Mae Wong National Park, Chong Yen, Kamphaeng Phet, Chayam. ET AL. 1551, holo L; iso AAU, BKF, K).

    E c o l o g y.— Altitude: 1340 m. Fruiting in July.

16. Mallotus lanceolatus (Gagnep.) Airy Shaw, Kew Bull. 21: 381. 1968; Kew Bull. 26: 303. 1972; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 404. 2007.— Coelodiscus lanceolatus Gagnep., Not. Syst. 4: 50. 1923.— Mallotus hainanesis S.M.Hwang, Acta Phytotax. Sin. 23: 293. 1985.— Mallotus cuneatus auct. non Ridl.: Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 98. 2000.

Undershrubs to trees, up to 6 m tall. Indumentum sparse, simple and stellate hairs, whitish glandular scales. Stipules dagger-like, triangular, stiff, 2-4 by 0.8-1 mm, somewhat sulcate at base. Leaves opposite; petiole 0.2–3.2 cm; blade elliptic to obovate, 2.3–12.5 by 1–6.5 cm, length/width ratio 2.3–3.7, drying brownish, base narrowly emarginate, margin denticulate to subentire to crenulate, especially in upper ²/₃^rd, with glandular teeth; apex acuminate, often mucronulate, upper surface shiny, glabrous, with up to 7 extrafloral nectaries from base along margin on basal nerve or outside basal nerve, lower surface only with glandular scales, few hairs on nerves, pit domatia present, venation triplinerved. Inflorescences terminal (to axillary), single, not branched. Staminate inflorescences up to 6.5 cm long; flowers in groups of up to 7 per node; bracts triangular, 1–2.2 by 1–3.3 mm. Staminate flowers 4.5–6.3 mm in diameter, yellowish, fragrant; pedicel 1.5–1.7 mm long; sepals 3 or 4, elliptic, 1.5–2.2 by 0.7–1.7 mm; stamens 35–40, filaments 1.3–1.7 mm long, white, anthers 0.3–0.4 m long. Pistillate inflorescences up to 12 cm long, erect; bracts triangular, 1.4–2.3 by 0.6–1.3 mm. Pistillate flowers 2.5–3.5 mm in diameter, green to white to brown; pedicel 1.5(–3 in fruit) mm long; sepals 4 or 5(6), triangular, 2.3–2.8 by 0.7–1.2 mm; ovary 3-locular, 1–1.3 by 1–1.6 mm, set with up to 1.3 mm long spines; style 0.6–1 mm long; stigmas 1.8–2.3 mm long. Fruits lobed capsules, 6–7 by c. 3 mm, green to brownish, sparsely set with spines, few hairs and glandular scales; column 2–2.5 mm long. Seeds subglobose, c. 3 by 2.8 by 2.5 mm.

     T h a i l a n d.— NORTHERN: Lampang (Chae Son), Tak (Doi Amphang); NORTH-EASTERN: Loei (Pha Nok Khao), Udon Thani (Nong Bua), Khon Kaen (Dong Lan, Pha Nu Khao, Phu Wiang, Tham Pha Phuang); EASTERN: Chaiyaphum (Nam Phrom, Phu Khiao), Nakhon Ratchasima (Khao Phrik, Khao Yai, Lat Bua Khao, Pak Chong); SOUTH-WESTERN: Phetchaburi (Klong Yang); CENTRAL: Saraburi (Khao Ma Kok, Muak Lak, Saraburi); SOUTH-EASTERN: Prachin Buri (Khao Yai), Chon Buri (Bang Phlat); PENINSULAR: Phuket, Surat Thani (Khao Sok), Yala (Wat Tam).

    D i s t r i b u t i o n.— Thailand, Indochina, Malay Peninsula (type).

    E c o l o g y.— Often common in dry evergreen and/or deciduous forest, bamboo forest, also in fire-prone thickets and near villages; soil: limestone. Altitude 5–650 m.

    V e r n a c u l a r.— Pho (โผ) (Central).

    N o t e.— Material from the Peninsula tends to have larger, more hairy leaves with more glandular scales on the lower surface.

17. Mallotus leptostachyus Hook.f., Fl. Brit. Ind. 5: 435. 1887; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 183. 1914; Airy Shaw, Kew Bull. 26: 300. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 101. 2000; S.E.C.Sierra, Welzen & Slik, Blumea 50: 226, fig. 2, map 1. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 405, Fig. 26. 2007.

Shrubs to trees, up to 6 m high. Indumentum covering most parts, simple and stellate hairs, orange to red glandular scales. Stipules triangular, 1.7–2.2 by c. 0.4 mm. Leaves alternate (to opposite below inflorescences); petiole 1–6 cm long; blades elliptic, 9.5–24 by 4.2–11.4 cm, length/width ratio 2–4.1, drying brownish, base cuneate, margin subentire with glandular teeth, apex cuspidate to caudate, upper surface glabrous except for some nerves, basally near insertion with two rather big extrafloral nectaries on basal nerves, 1–2 by c. 0.4 mm, lower surface (densely) hairy on venation, glandular scales, no domatia; venation triplinerved. Inflorescences terminal or axillary, single, not branching. Staminate inflorescences up to 19 cm long; flowers in groups of up to 6 per node; bracts triangular, c. 1.2 by 0.3 mm. Staminate flowers c. 4 mm in diameter, greenish white; pedicel 1–1.3 mm long; sepals 3, elliptic, 1.7–2.5 by 1.2–1.8 mm; stamens c. 60, filaments 1.4–2.5 mm long; anthers c. 0.3 mm long. Pistillate inflorescences up to 6.5 cm long; bracts triangular, c. 1 by 1 mm. Pistillate flowers c. 4 mm in diameter; pedicel c. 1.5 mm long; sepals 3, ovate to elliptic, c. 1.8 by 0.8–1.2 mm; ovary 3-locular, c. 2.3 by 1 mm, densely villose, not armed; style c. 0.2 mm long; stigmas c. 2 mm long. Fruits not seen, unarmed.

    T h a i l a n d.— SOUTH-WESTERN: Kanchanburi (Songkhla); PENINSULAR: Chumphon (Ban Kraye, Hot Spring Forest Park), Ranong (Khao Pawa Luangkaeo, La-un).

    D i s t r i b u t i o n.— Lower Myanmar (type), Thailand.

    E c o l o g y.— Evergreen forest by stream. Altitude: 1.5–600 m.

18. Mallotus leucocalyx Müll.Arg. in DC., Prodr. 15, 2: 970. 1866; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 405. 2007.— Mallotus dispar auct. non (Blume) Müll.Arg.: Airy Shaw, Kew Bull. 26: 303. 1972, p.p., pro synonym M. leucocalyx.

Shrubs to treelets, up to 8 m high, dbh up to 10 cm, dioecious. Outer bark smooth, grey-brown; inner bark pale yellow. Indumentum sparse to villous, simple and stellate hairs, glandular scales yellow-orange. Stipules elliptic to obovate, 4–10 by 2–6 mm. Leaves opposite, both similar shape; petiole 4.1–10 cm long; blade elliptic to obovate, 10.5–26 by 5.8–15 cm, length/width ratio 1.5–1.9, drying greenish, base not peltate to subpeltate to up to 1 mm, narrowly emarginate to rounded to cuneate, margin (shallowly) dentate with glandular teeth, apex acute to acuminate, upper surface sparsely hairy, extrafloral nectaries small, elliptic to orbicular, 0.3–0.5 by 0.3–0.5 mm, 2–12 marginal nectaries per side, 1–7 mm from margin, lower surface sparsely hairy, with numerous glandular scales, domatia absent, venation triplinerved, nerves 8 or 9 per side. Inflorescences axillary to terminal, single, up to 16 cm long, densely hairy; bracts trilobed, 5–10 by. 2.8–3.1 mm. Staminate flowers 3–4.2 mm in diameter; pedicels 2–4 mm long; sepals 3 or 4, elliptic to obovate, 2.5–2.8 by 0.7–1.2 mm, apex acuminate; stamens 20–40, filaments 1–3 mm long, anthers ovoid, 0.2–0.3 by 0.2–0.3 mm; pistillode present. Pistillate flowers 2.8–3 mm in diameter; pedicels 1–2 mm long; sepals 3–6, triangular, 3.8–4.1 by 0.8–1 mm, apex acute; ovary 1.8–2 by 1.8–2 mm, 3-locular, with spines; style 1.5–2 mm long; stigma 4–5 mm long. Fruits dehiscent rhegmas, 7–7.5 by 9–11 mm, hairy, glandular scales present, spines 200–230; wall 0.7–1 mm thick, inside hairy; column 3.4–5 mm long. Seeds subglobose, 3.2–4.2 by 3–4 by 3–3.8 mm, shiny, light brown; aril absent.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Khao Luang); PENINSULAR: Chumphon (Bang Son, Ta Ngao), Surat Thani (Ko Samui, Khao Tan, Ko Wang, Khao Mok, Ko Prap, Tha Khanon), Phangnga (Ao Luk, Ko Surin Nua, Suwana Koha Cave), Phuket (Khao Tosae), Krabi (Klong Chilat), Nakhon Si Thammarat (Khao Long), Phatthalung (Khao Pu-Khao Ya), Trang (Khao Sibong), Satun (Ban Tan),

    D i s t r i b u t i o n.— Myanmar (Burma), Thailand, Malay Peninsula, Sumatra, Java, Borneo (Sabah), Sulawesi and the Philippines.

    E c o l o g y.— Locally common in understory of primary to secondary forests, in open or shaded areas; on clay, or limestone, or soil. Altitude: sea level up to 638. Altitude 0–638 m. Flowering and fruiting the whole year through.

19. Mallotus leucodermis Hook.f., Fl. Brit. Ind. 5: 441. 1887; Airy Shaw, Kew Bull. 16: 350, 352. 1963; Kew Bull. 20: 39. 1966; Kew Bull. 21: 397. 1968; Whitmore, Tree Fl. Mal. 2: 116, fig. 10. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 167. 1975; Bollendorff et al., Blumea 45: 326, fig. 1b, 2a, 3, map 2. 2000; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 101. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 407, Fig. 27: A, B. 2007.

Shrubs or trees, up to 35 m high. Indumentum almost absent, few stellate and simple hairs, many yellowish to orange-red glandular scales. Stipules triangular, 1.5–2.5 by 0.6–0.8 mm. Leaves subopposite to alternate; petiole 1.8–8.5 cm long; blade ovate to obovate, 9.8–27 by 3.5–14 cm, length/width ratio 1.9–2.8, drying brownish, base narrowly obtuse to cordate, margin entire to slight crenate, seldom dentate, glandular in sinuses, apex acuminate to caudate, upper surface glabrous, subbasally with 0–5 extrafloral nectaries, 1.2–1.5 by 0.5–0.8 mm, many glandular scales; lower surface with glandular scales and often hair tuft domatia, venation triplinerved. Inflorescences axillary or terminal, solitary or in pairs (rarely by 3), unbranched. Staminate inflorescences 7–16 cm long; flowers in groups of 3–5 per node; bracts triangular to ovate, 0.5–0.7 by 0.8–1 mm. Staminate flowers 2.2–5 mm in diameter; pedicels 1–3 mm long; sepals 2–4, ovate, 2.1–3.5 by 1.3–2 mm; stamens 26–37, filaments 1.5–3 mm long, anthers 0.3–0.8 mm long. Pistillate Inflorescences 10.5–36(–60) cm long; bracts rhomboid, 0.6–1.5 by 0.8–1.6 mm. Pistillate flowers 2–3 mm in diameter; pedicels 5(–40 in fruit) mm long; sepals (5)6, triangular, 1.5–3 by 0.3–1.2 mm; ovary (2)3(4)-locular, covered with glandular scales, not armed; style 0.2–1.5 mm long; stigmas 2–3.5 mm long. Fruits tardily dehiscent, strongly lobed capsules, 6–25 by 5–15 mm, not armed, with glandular scales, yellowish brown to green; column 5.5–8 mm high. Seed subglobose, 4–7 mm in diameter.

    T h a i l a n d.— PENINSULAR: Narathiwat (Phi Ramin).

    D i s t r i b u t i o n.— Thailand, Peninsular Malaysia (type), Sumatra, and Borneo.

    E c o l o g y.— Primary and secondary forest, peat swamp forest; soil: brown (basalt derived?). Altitude: 0–45 m.

    V e r n a c u l a r.— Ka dongdong (กะดองดง) (Peninsular).

20. Mallotus macrostachyus (Miq.) Müll.Arg. in DC., Prodr. 15, 2: 963. 1866; Hook.f., Fl. Brit. Ind. 5: 429. 1887; Gagnep. in Lecomte, Fl. Indo-Chine 5: 357. 1925; Airy Shaw, Kew Bull. 26: 297. 1972; Whitmore, Tree Fl. Mal. 2: 114. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 165. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 101. 2000; S.E.C.Sierra & Welzen, Blumea 50: 254, fig. 2, map 2. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 407, Fig. 28, Plate XXI: 3.— Rottlera macrostachya Miq., Fl. Ind. Bat. Suppl.: 454. 1860.— Mallotus insignis Müll.Arg., Linnaea 34: 193. 1865.— Mallotus albus auct. non Müll.Arg.: Müll.Arg., Linnaea 34: 188. 1865, p.p., pro Motley 530, Wallich 7820.

Shrubs to trees, up to 16 m high. Indumentum densely, stellately, patently hairy; orangish glandular scales. Stipules triangular, 2.5–3.5 by 1–1.3 mm. Leaves alternate to usually opposite beneath inflorescences; petiole 1.8–23.5 cm long; blade ovate, 10.5–39 by 9.8–30 cm, length/width ratio 1.2–1.3, drying brownish, base truncate to rounded, slightly peltate up to 1.5 mm, protruding upwards, margin entire to somewhat coarsely denticulate, probably not lobed, apex caudate, with usually 2 small extrafloral nectaries near insertion on horizontal nerves, 1–2.5 by 0.3–1.3 mm, lower surface densely hairy, covered with orangish glandular scales, venation palmate. Inflorescences terminal, single. Staminate inflorescences erect, up to 101 cm long, side branches up to 65 cm long, flowers in groups of up to 6 per node; bracts triangular c. 0.9 by 1 mm. Staminate flowers 4–4.5 mm in diameter, whitish to yellow, fragrant; pedicel 2.8–4.2 mm long; sepals 4, elliptic, 2.5–2.9 by 1.2–1.9 mm; stamens 50–70, light yellowish, filaments 1.3–2.5 mm long, anthers c. 0.4 mm long. Pistillate inflorescences becoming pendent, up to 56 cm long, seldom with a few side branches up to 13.5 cm long; bracts ovate, 0.8–1.1 by 0.8–1.1 mm. Pistillate flowers 2.3–2.5 mm in diameter (without stigmas), white to greenish; calyx 2.3–4 mm high, 3–6-lobed, lobes triangular, 1–1.5 by 1.2–1.8 mm; ovary as wide as style when young, 3-locular, 2–2.3 by c. 1.2 mm; style 1.4–1.8 mm long; stigmas c. 4 mm long. Fruits lobed capsules, 12–16 by 10–13 mm, light yellowish to brown rhegmas, uniformly, densely covered with a layer of up to 5 mm long spines, latter densely stellately hairy and individually hardly visible; column 4–5 mm long. Seeds obovoid, 4–5 by 4–4.5 by 3.8–4 mm, black.

    T h a i l a n d.— PENINSULAR: Chumphon (Pata), Ranong (Pak Chan, Phahad beach), Surat Thani (Khao Habsib), Phuket (Khao Prathaeo), Krabi (Nong Le), Nakhon Si Thammarat (Chawang, Khao Luang, Kung Ching Waterfall), Trang (Khao Chong), Songkhla (Ton Nga Chang, Ko Hong, Rattapume), Yala (Banang Sata, Klong Mu Bo, Thanto), Narathiwat (Bala-Hala, Waeng).

    D i s t r i b u t i o n.— Thailand, Malay Peninsula, Sumatra (Bangka Island; type), Borneo.

    E c o l o g y.— Usually in disturbed habitats in evergreen forest, along roads, edges of forest, open thickets, along rivers; limestone bedrock. Altitude: 0–500 m.

    V e r n a c u l a r.— Plao yai (เปล้าใหญ่), Lua (ลัว) (Nakhon Si Thammarat); Fami (ฝามี), Lo khon (หลอขน) (Trang); Lo (หลอ) (Narathiwat); Common pom-pom tree (English).

    N o t e.— See note under Mallotus tetracoccus.

21. Mallotus metcalfianus Croizat, J. Arnold. Arbor. 21: 501. 1940; S.M.Hwang in H.S.Kiu, Fl. Reipubl. Popularis Sin. 44(2): 39. 1996; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 409. 2007.— Mallotus mollissimus auct. non (Geiseler) Airy Shaw: Airy Shaw, Kew Bull. 26: 297. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 102. 2000, both p.p. (see note).

Shrubs to trees, to 6 m high. Indumentum very densely tomentose, yellowish and dark brown stellate hairs, glandular scales yellow to orange. Outer bark red and chocolat brown. Stipules triangular to subulate, c. 2 by 1.2 mm, completely tomentose. Leaves brownish when young, alternate to usually opposite beneath inflorescences; petiole 1-12 cm long; blade ovate, 3.5-19.3 by 3.1-14.5 cm, length/width ratio 1-1.4, drying dark brownish above, light brownish beneath, base truncate to rounded, slightly peltate up to 13 mm, margin laxly serrate above largest width, apex acuminate (to cuspidate), upper surface hairy on midrib and basal nerves, glabrescent, extrafloral nectaries long elliptic, (0 or) 2 or 4, near insertion on the more or less horizontal nerves, c. 1 by 0.7 mm, subapically sometimes 1 or 2 extrafloral nectaries near margin, lower surface densely tomentose, epidermis and glandular scales not visible, domatia absent; venation palmate, nerves 6-8 per side above insertion. Inflorescences (axillary to) terminal panicles, single, unisexual, up to 26 cm long; bracts triangular, 2-3.8 by 0.8-1 mm. Staminate flowers yellowish white to yellow, 6-7 mm in diameter; pedicels 5-5.8 mm long; buds dull brown; sepals 3, elliptic, 3.6-4 by 1.7-2.8 mm, reflexed, outside hairy; stamens 70-80, filaments 3.2-4.5 mm long, free, anthers 0.2-0.3 by 0.2-0.3 mm. Pistillate flowers not seen. Fruits lobed rhegmas, 3- or 4-locular, 15-17 by 13-16 mm (incl. spines), tomentose, with c. 400 spines of about 7 mm long, individual spines visible; wall c. 0.2 mm thick; column 5-5.5 mm long. Seeds subovoid, c. 5.5 by 4.5 by 4 mm, surface shiny black, warty, aril absent.

    T h a i l a n d.— NORTH-EASTERN: Nong Khai (Bungkla, Ponepisai).

    D i s t r i b u t i o n.— Thailand, Vietnam, S. China (Guangxi Prov.).

    E c o l o g y.— Secondary forests, forest margins, (submontane) evergreen forest. Altitude: 400-600 m.

    V e r n a c u l a r.— Plao thong (เปล้าทอง) (North-eastern).

    N o t e s.— 1. Mallotus mollissimus does not occur in Thailand, it was confused with M. metcalfianus and M. tetracoccus, which both resemble M. mollissimus very closely, especially when only staminate flowers are available. Mallotus metcalfianus is very similar to M. mollissimus, both have the same type of fruit. The fruit of M. tetracoccus is very different, far fewer spines, which are much shorter and stouter. Mallotus metcalfianus differs from M. mollissimus in the almost absence of extrafloral nectaries along the edge of the adaxial leaf blade (many in M. mollissimus), on the lower surface the indumentum is dense (epidermis and glandular scales not visible) and the stellate hairs are partly dark brownish (epidermis and glandular scales visible in M. molissimius, hairs yellowish), pistillate calyx connate (basally connate in M. mollissimus), ovary 3- or 4-locular (3-locular in M. mollissimus), fruit spines densely hairy (less so in M. mollissimus).

    2. See also note under Mallotus tetracoccus.

22. Mallotus miquelianus (Scheff.) Boerl., Handl. 3, 1: 290. 1900; Airy Shaw, Kew Bull. 26: 295. 1972; Whitmore, Tree Fl. Mal. 2: 114. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 163. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 102. 2000; Slik & Welzen, Blumea 46: 55, Fig. 22, Map 9. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 411, Fig. 29. 2007.— Rottlera miqueliana Scheff., Ann. Mus. Bot. Lugd.-Bat. 4: 124. 1868.— Mallotus anisophyllus Hook.f., Fl. Brit. Ind. 5: 435. 1887.

Shrubs to trees, up to 10 m high. Indumentum of long and short simple hairs, few stellate hairs, orangish glandular scales. Stipules triangular, 4–13 by 1.8–3 mm. Leaves opposite, one much smaller and with different shape; petiole 2–7 mm long; blade of normal leaves elliptic (to obovate or ovate), 7–32 by 2.3–13 cm, length/width ratio 2–4.7, drying brownish, base oblique, one side cuneate, other emarginate, margin wavy to dentate with marginal glands, apex acuminate to cuspidate, upper surface glabrous, basal extrafloral nectaries 2–6 on basal nerves, 0.7–1.8 mm in diameter, subapical extrafloral nectaries 2–13 per side, much smaller, between nerves, lower surface glabrous except for hair tufts in domatia, few glandular scales, venation penninerved; reduced leaves c. orbicular, 0.8–5.5 by 0.8–4.8 cm, base cordate, upper surface with usually 2 basal extrafloral nectaries. Inflorescences axillary (to terminal), in axil of reduced leaf, single, not branching. Staminate inflorescences up to 13.5 cm long; flowers up to 6 per node; bracts trapezoid, 1.5–3 by 0.9–1.7 mm. Staminate flowers 2.5–6 mm in diameter, yellow-green to whitish; pedicels 2.5–5.5(–10) mm long; sepals (2 or) 3, ovate to elliptic, 1.8–5 by 1–1.8 mm; stamens up to 55, filaments 2.3–4.5 mm long; anthers c. 0.3 mm long. Pistillate inflorescences up to 10 cm long; bracts trapezoid, 3–4.5 by 1–2 mm. Pistillate flowers dirty green to yellow-white to purplish-brown; pedicels 1–6 mm long; sepals 3, ovate 3–8 by 1.3–3.3 mm; ovary 3(4)-locular, echinate, spines 0.8–1.5 mm long with simple hairs and glandular scales; style c. 1 mm long; stigmas up to 5(–9) mm long. Fruits lobed capsules, 8–12 by 5–7 mm, sparsely echinate, green to brown-red; column c. 3–4 mm wide. Seeds globose, 4–4.5 mm in diameter.

    T h a i l a n d.— PENINSULAR: Nakhon Si Thammarat (Ta Samet), Songkhla (Khao Su Dao, Ton Nga Chang).

    D i s t r i b u t i o n.— Thailand, Malay Peninsula, Sumatra, Borneo (type), Philippines.

    E c o l o g y.— Evergreen forest, but mainly in disturbed sides, often inundated or wet places; soil: wide variety from sandy soils to clayey loam to limestone. Altitude: up to 700 m.

    U s e s.— Wood can be used for walking sticks. Plant can also act as poison.

23. Mallotus mirus S.E.C.Sierra, Blumea 52 (2007) 81, Fig. 8, Map 1.— Mallotus sp. nov.: Airy Shaw, Kew Bull. 21: 396. 1968; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 413. 2007. ---Type: Kerr 19835 (holo L, iso BM, K), Thailand, Prachinburi Circle, Kao Singto, Krabin.

 Shrubs, up to 0.5 m high, dioecious. Indumentum simple and stellately tufted hairs, sparse to scattered, glandular scales white. Stipules triangular, 6–6.5 by 1.5–2 mm, persistent. Leaves opposite, of similar shape; petiole 10–33 mm long, not pulvinate, sparsely hairy; blade obovate, 14–22 by 5.5–9 cm, length/width ratio 2–2.9, base acute, margin undulate to sinuate, apex cuspidate, upper surface hairy on midrib and nerves, basally with 2 or 3 extrafloral nectaries per side, 1–6 mm from margin, elliptic, 0.7–0.9 by 0.3–0.5 mm, 4–8 marginal nectaries per side, 4–5 mm from margin, orbicular, 0.2–0.3 by 0.2–0.3 mm, lower surface sparsely hairy, with few glandular hairs, domatia absent, venation penninerved, nerves 7–9 per side. Inflorescences axillary to terminal, single, erect; staminate ones unknown; pistillate ones reduced to a single terminal flower with a crown of bracts. Pistillate flowers unknown. Fruits opening septicidally-loculicidally, hairs scattered, without glandular scales; calyx 5- or 6-lobed, basally connate, 8-10 by 1.5-2 mm; wall 0.8 mm thick, inside glabrous; column 6 by; 5 mm; Seeds subglobose, 6–7.8 by 5–6 by 5–6 mm, smooth, dull, light brown; aril absent.

    T h a i l a n d.— SOUTH-EASTERN: Prachin Buri (Kabin Buri).

    D i s t r i b u t i o n.— Endemic to Thailand (type: Prachinburi Circle, Kao Singto, Krabin, KERR 19835, holo in L, iso in BM, K).

    E c o l o g y.— In evergreen forest on limestone hill. Altitude 50 m. Fruiting November.

    N o t e.— M. sp.nov.2 resembles M. calocarpus closely, but M. sp.nov.2 has flattened tufted hairs (raised and tufted in M. calocarpus), scattered hairs on fruits and petioles (densely hairy in M. calocarpus), and an acute leaf base (attenuate in M. calocarpus). Although, both species occur in southeastern Thailand, M. sp.nov.2 is only know from Prachin Buri and M. calocarpus is endemic to Chanthaburi and Narathiwat.

24. Mallotus montanus (Müll.Arg.) Airy Shaw, Kew Bull. 32: 78. 1977; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 102. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 413. 2007.— Croton montanus auct. non Willd.: Wall., Cat.: 7223B. 1847, nom. nud.— Coelodiscus montanus Müll.Arg. in DC., Prodr. 15, 2: 759. 1866.— Mallotus eriocarpus auct. non Müll.Arg: Pax & K. Hoffm. in Engl., Pflanzenr. IV.147.vii: 160. 1914; Whitmore, Tree Fl. Mal. 2: 115. 1973, p.p., pro specim. Malacca.

Shrubs to trees, up to 6 m tall. Indumentum of stellate and simple hairs, whitish glandular scales. Stipules early caducous. Leaves opposite; petiole 1.5–7 cm long; blades ovate, 5.4–18 by 3–10 cm, length/width ratio 1.8–2.7, drying greenish, base cordate (to truncate), margin laxly serratulate with glandular teeth, apex acuminate to cuspidate, upper surface hairy, usually with 1 or 2 pairs of small extrafloral nectaries in lowest lobes, sometimes also along margin, lower surface with hairs and scales, some hair tufts in lower nerve axils, venation palmate to triplinerved. Inflorescences racemes axillary to terminal, single, peduncle 0.7-3.5 cm long; bracts densely hairy outside. Staminate flowers 3-3.5 mm in diameter; pedicels 1.2-1.5 mm long; sepals 3(4), free, ovate, 2.5-3 by 1.3-1.5 mm; stamens 20-30, filaments 2-3 mm long; anthers 0.2-0.3 mm long. Pistillate inflorescences terminal (or axillary), with 1 or 2 apical flowers, 3-7 cm long; bracts triangular, c. 1.5 by 1.1 mm. Pistillate flowers c. 4 mm in diameter; pedicel up to 25 mm in fruit; sepals 3 or 4(–6), triangular, c. 3 by 1–1.5 mm, brownish; ovary 3-locular; style 0.5–1 mm long; stigmas 1.8–2.8 mm long. Fruits triangular, lobed capsules, c. 19 by 13 mm, grey-green, not echinate, densely hairy and with glandular scales; column c. 4.5 mm long. Seed globose, c. 6 mm in diameter.

    T h a i l a n d.— PENINSULAR: Trang (Khao Chong), Songkhla (Ko Hong Hill), Narathiwat (Bacho, Waeng).

    D i s t r i b u t i o n.-Thailand, Malay Peninsula (type).

    E c o l o g y.— Shaded area in secondary or evergreen forest. Altitude: 150–400 m.

25. Mallotus nudiflorus (L.) Kulju & Welzen, Blumea 52: 124. 2007. — Trewia nudiflora L., Sp. Pl.: 1193. 1753; Kurz, For. Fl. Burm. 2: 379. 1877; Hook.f., Fl. Br. Ind. 5: 423. 1885; Craib, Bull. Misc. Inf.: 466. 1911; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 140. 1914; Gagnep. in Lecomte, Fl. Indo-Chine 5: 343. 1925; Backer, Fl. Java. 1: 481. 1963; Airy Shaw, Kew Bull. 20: 405. 1966; Kew Bull. 23: 79. 1969; Kew Bull. 26: 343. 1972; Whitmore, Tree Fl. Malaya 2: 134. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 200. 1975; Kew Bull. 36: 350. 1981; Vu Van Dung, Vietnam. For. Tr.: 249. 1996; Susila & Balakr., J. Econ. Tax. Bot. 22: 345. 1998; Gardner et al., For. Trees North. Thailand: 322. 2000; Kulju, Welzen & Nanakorn in Welzen & Chayam., Fl. Thailand 8, 2: 569, Fig. 90, Plate XXIX: 4. 2007.— Trewia integerrima Stokes, Bot. Mat. Med. 4: 570 (‘Treuia’). 1812, nom. superfl.— Rottlera indica Willd., Gött. J. Naturwiss. 1: 8. 1798.— Trewia macrophylla Roth, Nov. Pl. Sp.: 373. 1821, non Blume, 1825.— Trewia macrostachya Klotzsch, Bot. Ergebn. Reise Waldemar: 117, t. 23. 1862.— Mallotus cardiophyllus Merr., Philipp. J. Sc. 7: 398. 1912.— Trewia nudiflora L. var. nudiflora: Susila & Balakr., J. Econ. Tax. Bot. 22: 347, t. 1. 1998.— Trewia nudiflora L. var. tomentosa Susila & Balakr., J. Econ. Tax. Bot. 22: 351, t. 3. 1998.

Deciduous tree up to 30 m high; often with buttresses; twigs glabrous to hairy. Outer bark thin, smooth (to slightly rough), grey to brown (to tan), sometimes patchy. Stipules 1.8-5.2 by 0.5-1.5 mm, hairy outside, (sub)glabrous inside. Leaves: petiole 1.8-12 cm long, glabrous to hairy; blade 6-21 by 6.3-16.5 cm, length/width ratio 1-2.3(-4.8 in immature leaves), membranous, base cordate to obtuse (to cuneate when immature), with 2-5 macular glands, margin without to up to 20 macular glands per side, apex (acute to) acuminate, lower surface glabrous to densely hairy, sometimes hair tuft domatia, glandular scales absent or very sparse; nerves 3-7 pairs. Staminate inflorescences up to 30 cm long; bracts 1.5-3.9 by 0.8-1.7 mm. Staminate flowers 4.7-9 mm in diameter, greenish creamy; pedicels 3.9-10 mm long; sepals (ovate to) elliptic, (3.2-)3.7-6 by (1.8-)2.1-3.7 mm; filaments 1.1-6 mm long, thecae 0.8-1.7 by 0.3-0.6 mm. Pistillate inflorescences up to 10.5 cm long; bracts 1.2-3.2 by 0.5-2.1 mm. Pistillate flowers: pedicel 1.1-9 mm long; calyx 4.7-6.4 mm long; style (1.7-)2.4-4.5(-5.9) mm long; stigma 12-24 mm long. Fruits 18-29 by 21-35 mm when dry, up to 35 by 45 mm when fresh, pericarp 2-8 mm thick when dry. Seeds 8-12 by 7-10 by 6-8 mm.

     Thailand.— Throughout the country.

    Distribution.— From India (type), Nepal, and, Sri Lanka, throughout Southeast Asia main land to southern China and W. Malesia (Malay Peninsula, Sumatra, Java, Borneo, Philippines).

    Ecology.— Deciduous to evergreen forest, usually in disdurbed and (partly) open sites, common along streams, on various soil types, dry to wet. In Nepal fruits are dispersed by rhinoceros and cattle. Altitude: up to 1,200 m. Flowering mainly December to April, fruiting May to September.

    Vernacular.— Ma pop (มะปอบ) (Northern); ma fo (มะฝ่อ) (General); mo-nae (ม่อแน่ะ), se-tho-khlue (เส่โทคลึ) (Karen-Mae Hong Son); ma-thi (หม่าทิ) (Karen-Kanchanaburi).

    Uses.— A fast growing pioneer species along streams. The wood is not durable and not available in large quantities, used for inside furniture and tools. Leaves used as fodder in Nepal. Medicinal use: to remove swellings and bile, to relieve flatulence, for gout and rheumatic afflictions (India, Nepal).

26. Mallotus pallidus (Airy Shaw) Airy Shaw, Kew Bull. 32: 78. 1977; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 103. 2000; S.E.C.Sierra, Welzen & Slik, Blumea 50: 228, fig. 3, map 1. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 414, Fig. 30, Plate XXII: 2. 2007.— Mallotus philippensis (Lam.) Müll.Arg. var. pallidus (‘pallida’) Airy Shaw, Kew Bull. 26: 300. 1972.

Shrubs to trees,up to 6 m high. Indumentum of simple and stellate hairs, glandular scales whitish to yellow. Stipules long triangular, 3.5–5.5 by 0.4–0.6 mm. Leaves alternate to apically opposite; petiole 0.3–2.8 cm long; blade ovate, 2.8–14.5 by 1.1–4.7 cm, length/width ratio 2.5–3.5, drying usually greenish, base round to somewhat emarginate, margin entire, apex bluntly acuminate to caudate, often mucronulate, upper surface (sub)glabrous, with 2 elongated black extrafloral nectaries, up to 1.2 by 0.4 mm, sometimes 2 small extra ones, lower surface subglabrous to densely villose, white when densely hairy, with glandular scales; venation palmate to triplinerved. Inflorescences terminal to axillary, single, unbranched. Staminate inflorescences up to 12.5 cm long; flowers in groups of c. 6; bracts ovate, 2.2–3.3 by 1.2–1.3 mm, caducous. Staminate flowers 4–5 mm in diameter; pedicel 2.3–5.2 mm long; sepals 3 or 4, ovately elliptic, 2.3–2.8 by 1–1.7 mm; stamens 55–70, filaments 1–3 mm long, anthers 0.3–0.4 mm long. Pistillate inflorescences up to 12 cm long; bracts triangular to ovate, 4–4.3 by 1.1–1.3 mm. Pistillate flowers 2.3–4 mm in diameter; pedicel 1.2–4 mm long; sepals 5, ovately elliptic, 3.6–3.7 by 0.9–1.2 mm; ovary 3-locular, 1.2–3.2 by 1.2–2.7 mm, unarmed; style absent to 0.5 mm long; stigmas 1–3 mm long. Fruits only seen young, lobed capsules, at least 6 by 5 mm, unarmed.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Khao Dang/Deang, Sam Roi Yot).

    D i s t r i b u t i o n.— Endemic in Thailand (type: Sam Roi Yot, Prachuap Khiri Khan, PUT 2489, holo in K, iso in BK).

    E c o l o g y.— Dry limestone hills near sea. Altitude: 0–250 m.

    V e r n a c u l a r.— Kra duk kai khao (กระดูกไก่ขาว) (South-western).

    N o t e.— This species can easily shed most of its indumentum present on the leaves, sometimes only parts between nerves become glabrous. The look of the leaves then changes dramatically from whitish below to greenish.

27. Mallotus paniculatus (Lam.) Müll.Arg. var. paniculatus: S.E.C.Sierra & Welzen, Blumea 50: 263, fig. 4, map 4; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 416, Fig. 31. 2007.— Mallotus paniculatus (Lam.) Müll.Arg., Linnaea 34: 189. 1865; Airy Shaw, Kew Bull. 26: 298. 1972; Whitmore, Tree Fl. Mal. 2: 114. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 166. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 103. 2000; S.E.C.Sierra & Welzen, Blumea 50: 261.— Croton paniculatus Lam., Encycl. 2: 207. 1786.— Echinus trisulcus Lour., Fl. Cochinch. 2: 633. 1790.— Mallotus cochinchinensis Lour., Fl. Cochinch. 2: 635. 1790.— Trewia tricuspidata Willd., Sp. Pl. 4: 835. 1805, nom. superfl.— Rottlera alba Roxb. ex Jack, Mal. Misc. 1: 26. 1820.— Rottlera paniculata (Lam.) Blume, Bijdr. 11: 604. 1826.— Mappa cochinchinensis (Lour.) Spreng., Syst. 3: 878. 1826,  nom. superfl.— Lasipania tricuspis Raf., Sylva Tellur. 22. 1838, nom. superfl.— Mallotus albus (Roxb. ex Jack) Müll.Arg., Linnaea 34: 188. 1865 (excl. M. macrostachyus, M. tetracocca).— Mallotus chinensis Lour. ex Müll.Arg. in DC., Prodr. 15, 2: 965. 1966.— Croton appendiculatus Elmer, Leafl. Philip. Bot. 1: 312. 1908.

Shrubs to trees about 20 m high. Indumentum densely stellately, patently hairy, glandular scales orangish. Stipules triangular, 0.5–1.2 by 0.3–0.8 mm. Leaves alternate (some opposite); petiole 2.2–16 cm long; blade ovate, 3.6–19.5 by 2.5–17 cm, length/width ratio 1.3–1.8, drying brownish, base usually slightly peltate, up to 1.5 mm, narrowly emarginate to round to usually cuneate, margin entire, seldom dentate, often with 2 lobes at widest part of blade, up to 3.5 cm long, apex cuspidate to caudate, upper surface with basally 2 large extrafloral nectaries near insertion, (1–)3 by (1–)2 mm, lower surface whitish because of hairs, (sparsely) with glandular scales, venation triplinerved. Inflorescences terminal, single, often branching. Staminate inflorescences up to 57 cm long, side branches up to 40 cm long, less than 1 mm thick; flowers in groups of up to 10 per node; bracts triangular, 0.4–0.8 by 0.6–1 mm. Staminate flowers 4–5 mm in diameter, fragrant; pedicel 1.3–3.2 mm long; sepals 3–5, ovate to elliptic, 2–2.8 by 0.8–1.8 mm, pale light yellow; stamens c. 50, filaments 1.2–2.7 mm long, whitish, anthers c. 0.4 mm long, light yellow. Pistillate inflorescences becoming pendent, up to 38 cm long, side branches up to 14 cm long; bracts triangular, 0.5–0.6 by 0.4–0.6 mm; bracteoles indistinct. Pistillate flowers 2–4 mm in diameter, yellow; pedicel 1.5–2(–2.5 mm in fruit) long; calyx with 4 or 5 lobes, 2–3 mm high, lobes ovate, 1.4–2.4 by 0.8–1 mm; ovary (2)3-locular, 1–1.8 by 1–2.5 mm, covered with c. 30 coarse spines up to 0.8 mm long; style 0.3–0.8 mm long; stigmas 2.2–2.5 mm long. Fruits lobed capsules, 5.5–6 by 4.2–4.5 mm, greenish brown to greyish-tan, densely hairy, covered with 10–20 course spines up to 4 mm long; column 2.8–3.5 mm long. Seeds subglobose, 2.8–3.5 by 2.8–3.5 by 2.4–3 mm, glossy black.

    T h a i l a n d.— NORTHERN: Chiang Mai, Chiang Rai, Lampang, Phrae, Tak, Sukhothai, Phitsanulok; NORTH-EASTERN: Phetchabun, Loei, Nong Khai, Sakon Nakhon, Khon Kaen; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Kanchanaburi, Phetchaburi, Prachuap Khiri Khan; CENTRAL: Saraburi, Nakhon Nayok; SOUTH-EASTERN: Sa Kaeo, Chon Buri, Rayong, Chanthaburi, Trat; PENINSULAR: Ranong, Surat Thani, Phangnga, Krabi, Nakhon Si Thammarat, Trang, Pattani, Narathiwat.

    D i s t r i b u t i o n.— Myanmar, Thailand, S. China, Taiwan, Indochina, throughout Malesia (Java: type) to Australia (Queensland).

    E c o l o g y.— Common pioneer in very secondary habitats like grassy clearings in montane mixed oak forest, dipterocarp forest, mixed deciduous forest; also along peat swamp margins, and along road sides and forest edges; soil: sandstone and granite bedrock. Altitude: 0–1500 m.

    V e r n a c u l a r.— Sati ton (สตีต้น) (Loei); Salat pang (สลัดป้าง), Soi dao (สอยดาว) (Chanthaburi, Trat); Lo khon (หลอขน) (Trang); Saet (แสด) (Peninsular); Turn-in-the-wind (English).

    N o t e.— See note under Mallotus tetracoccus.

28. Mallotus peltatus (Geisel.) Müll.Arg., Linnaea 34: 187. 1865; Airy Shaw, Kew Bull. 26: 307. 1972; Whitmore, Tree Fl. Mal. 2: 113. 1973; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 103. 2000; Slik & Welzen, Blumea 46: 41, fig. 16, map 7. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 418, Fig. 32. 2007.— Aleurites peltatus Geisel., Croton. Monogr.: 81. 1807.— Adisca acuminata Blume, Bijdr.: 610. 1826.— Rottlera acutifolia Hassk., Cat. Hort. Bog.: 238. 1844.— Mappa acutifolia (Hassk.), Zoll. & Moritzi, Syst. Verz.: 17. 1855.— Rottlera longifolia Rchb.f. & Zoll., Verh. Natuurk. Ver. Ned. Ind.1: 31. 1856.— Rottlera acuminata (Blume) Baill., Ét. Gén. Euphorb.: 46. 1858, non A.Juss., 1824.— Rottlera oblongifolia Miq., Fl. Ind. Bat. 1, 2: 396. 1859.— Hancea muricata Benth., Fl. Hongk.: 306. 1861.— Rottlera flavigutta Miq., Fl. Ind. Bat. Suppl.: 453. 1862.— Mallotus porterianus Müll.Arg., Linnaea 34: 185. 1865.— Mallotus acuminatus (Blume) Müll.Arg., Linnaea 34: 187. 1865.— Mallotus furetianus Müll.Arg., Linnaea 34: 190. 1865.— Mallotus helferi Müll.Arg., Linnaea 34: 190. 1865.— Mallotus lambertianus Müll.Arg., Linnaea 34: 190. 1865.— Mallotus oblongifolius (Miq.) Müll.Arg., Linnaea 34: 192. 1865.— Mallotus longifolius (Rchb.f. & Zoll.) Müll.Arg. in DC., Prodr. 15, 2: 967. 1866.— Mallotus longifolius (Rchb.f. & Zoll.) Müll.Arg. var. pubescens Müll.Arg. in DC., Prodr. 15, 3: 967. 1866.— Mallotus stylaris Müll.Arg. in DC., Prodr. 15, 2: 973. 1866.— Rottlera lambertiana (Müll.Arg.) Scheff., Ann. Mus. Bot. Lugd.-Bat. 4: 125. 1968–9.— Rottlera stylaris (Müll.Arg.) Scheff., Ann. Mus. Bot. Lugd.-Bat. 4: 125. 1868–9.— Mallotus puberulus Hook.f., Fl. Brit. Ind. 5: 435.1887.— Mallotus columnaris Warb., Bot. Jahrb. 13: 349. 1891.— Mallotus odoratus Elm., Leafl. Philipp. Bot. 4: 1299. 1911.— Mallotus alternifolius Merr., Philipp. J. Sci. 7, ser. C, Bot.: 395. 1912.— Mallotus camiguinensis Merr., Philipp. J. Sci. 7, ser. C, Bot.: 397. 1912.— Mallotus oblongifolius (Miq.) Müll.Arg. var. helferi (Müll.Arg.) Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 194. 1914.— Mallotus oblongifolius (Miq.) Müll.Arg. var. siamensis Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 194. 1914.— Mallotus maclurei Merr., Philipp. J. Sci. 21: 347. 1922.

Shrubs to trees, up to 10 m high, often (faintly) smelling of fenucreek. Indumentum of few short or long simple hairs, short stellate hairs, few glandular scales. Stipules triangular, 2–4 by 0.7–1.5 mm. Leaves alternate to opposite; petiole 0.4–7 cm long; blades ovate to obovate, 6–23 by 2.3–10 cm, length/width ratio 1.8–3.8, drying brownish, base deeply emarginate to round (to cuneate), not peltate to peltate up to 14 mm, margin subentire to usually denticulate with glandular teeth, apex cuspidate to caudate, upper surface glabrous, basally with 2–6 small blackish extrafloral nectaries on nerves below insertion, c. 0.3–0.5 mm in diameter, lower surface subglabrous, few glandular scales, usually pocket tufts in nerve axils; venation palmate. Inflorescences terminal to axillary, single or 2 together, unbranched. Staminate inflorescences up to 16 cm long; flowers in groups of up to 9 per node; bracts triangular, 0.9–1 by 0.9–1 mm. Staminate flowers 3–4.5 mm in diameter, scented; pedicel 1.6–2 mm long, green; sepals 2–4, ovate to elliptic, 1.6–3 by 0.7–1.3 mm, yellowish-light greenish; stamens 25–35, filaments 1–3.2 mm long, light (yellowish) green to white; anthers 0.2–0.3 mm long, cream. Pistillate inflorescences up to 21.5 cm long; bracts ovate, 2–2.9 by 1.6–1.7 mm. Pistillate flowers 3–4 mm in diameter, green (to red); pedicel 2(–4.5 in fruit) mm long; calyx urceolate, enclosing ovary and style closely, 4–6 mm high, apically with 2 small lobes, c. 1.2 by 0.7–1.3 mm, tearing apart and caducous, leaving ring-like scar in fruit, light yellow; ovary 3-locular, 1–2 by 1–2 mm, covered with spines up to 0.7 mm long; styles 2.8–4.5 mm long, stigmas 3–4.5 mm long, light yellowish. Fruits lobed capsules, 1–1.4 by 0.5–0.75 cm, green to wine red to brown with sparse, caducous, reddish spines and yellow glandular scales, subglabrous; column 3.3–4.5 mm long. Seeds subglobose, 4–5 mm in diameter, brown, often marbled.

    T h a i l a n d.— NORTHERN: Chiang Mai, Lampang, Phayao, Phrae, Uttaradit, Sukhothai, Nakhon Sawan; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Uthai Thani, Kanchanaburi, Prachuap Khiri Khan; CENTRAL: Saraburi, Nakhon Nayok; SOUTH-EASTERN: Prachin Buri, Chon Buri, Rayong, Chanthaburi; PENINSULAR: Ranong, Surat Thani, Pangnga, Phuket, Krabi, Nakhon Si Thammarat, Phatthalung, Trang, Satun, Songkhla, Pattani, Yala, Narathiwat.

    D i s t r i b u t i o n.— Myanmar, Andaman Islands, Thailand, Indochina, throughout Malesia to New Guinea.

    E c o l o g y.— In a large variety of vegetations, varying from deciduous (mixed) forest to evergreen forest, bamboo forest, mixed oak forest, often along water or in rocky areas, also in very disturbed places, like thickets, edges of forest, fields; soil: shale, limestone or granite bedrock. Alitude: 0–800 m.

    V e r n a c u l a r.— Salat (สลัด) (Chanthaburi); Khi tao (ขี้เต่า) (Ranong); Wild castor oil (English).

    N o t e.— Two widespread species in Thailand, M. oblongifolius and M. peltatus, have been united. The only difference between the two species is the absence or presence of a peltate leaf base. In all other characters, though often very variable (see high number of synonyms), they are the same. However, specimens with peltate leaves often also have non-peltate leaves (referred to M. peltatus), and specimens with non-peltate leaves often have slightly peltate leaves (always referred to M. oblongifolius). The peltation seemingly shows a continuum in Thailand and the separation into two species is artificial. Unfortunately, both names, of which peltatus is the oldest, are ill-fitting, many specimens are not peltate and very often the leaves are clearly ovate or elliptic instead of oblong. The combined taxon is highly distinctive due to its long acuminate staminate sepals, leaves which are almost devoid of hairs and glandular scales, and the high, urceolate pistillate calyx.

29. Mallotus philippensis (Lam.) Müll.Arg., Linnaea 34: 196. 1865; Hook.f., Fl. Brit. Ind. 5: 442. 1887; Merr., En. Philipp. 2: 340. 1921; Gagnep. in Fl. Gén. I.-C. 5: 362. 1025; Airy Shaw, Kew Bull. 21: 392. 1968; Kew Bull. 26: 300. 1972; Whitmore, Tree Fl. Mal. 2: 115. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 168. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 105. 2000; S.E.C.Sierra, Welzen & Slik, Blumea 50: 230, fig. 4, map 2. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 421, Fig. 33. 2007.— Croton philippense Lam., Enc. 2: 206. 1786. — Croton punctatus Retz. (‘punctatum’), Obs. Bot. 5: 30. 1789.— Croton coccineus Vahl, Symb. Bot. 2: 97. 1791.— Rottlera tinctoria Roxb., Pl. Corom. 2: 36, t. 168. 1802.— Croton montanum Willd., Sp. Pl. 4: 547. 1805.— Rottlera philippensis (Lam.) A.Juss. ex Spreng., Syst. Veg. (ed. 16) 3: 877. 1826.— Rottlera tinctoria Roxb. var. monstruosa Ham. ex Dillwyn, Rev. Hortus Malab.: 22. 1839— Rottlera aurantiaca Hook. & Arn., Bot. Beech. Voy.: 270. 1841.— Rottlera affinis Hassk., Flora 25, Beibl. 2: 41: 1842.— Mappa stricta Rchb.f. & Zoll., Verh. Natuurk. Ver. Ned. Ind. 1: 31. 1856.— Aconceveibum trinerve Miq., Fl. Ind. Bat. 1, 1: 389. 1859.— Macaranga stricta (Rchb.f. & Zoll.) Müll.Arg. in DC., Prodr. 15, 2: 1004. 1866.— Echinus philippensis (Lam.) Baill. (‘philippinensis’), Adansonia 6: 314. 1866.— Mallotus reticulatus Dunn., J. Linn. Soc. London 38: 365. 1908.— Euonymus hypoleucus H.Lév., Feddes Repert. 13: 260. 1914.— Mallotus philippensis (Lam.) Müll.Arg. var. tomentosus Gamble, Fl. Madras 2, 7: 1322. 1925.— Mallotus philippensis (Lam.) Müll.Arg. var. reticulatus (Dunn) F.P.Metcalf, J. Arnold Arb. 22: 207. 1941.— Mallotus bicarpellatus T.Kuros., Edinburgh J. Bot. 61: 31. 2004

Shrubs to trees up to 15 m high. Indumentum of short, woolly and long, stiff simple and stellate hairs, glandular scales red. Stipules triangular, 0.5–1.3 by 0.4–0.5 mm. Leaves alternate; petiole 1.5–5.2 cm long; blade ovate to elliptic, 4–22 by 2.1–10.5 cm, length/width ratio 1.9–4, drying greenish to brownish, base usually rounded, margin entire (to seldom dentate with glandular teeth), apex acuminate to cuspidate, upper surface glabrous except for a few basal glandular scales, with 2–4(–6) black extrafloral nectaries near insertion, up to 1.5 by 1 mm; lower surface densely hairy, many glandular scales, venation triplinerved. Inflorescences axillary and single to terminal and in groups up to 8, seldom with 1 or 2 branches. Staminate inflorescences up to 18 cm long; flowers in small groups of 3(4); bracts triangular, 0.7–0.8 by 0.6–0.9 mm; bracteoles distinct. Staminate flowers 2–3 mm in diameter, green, slightly fragrant; pedicel 1.8–3 mm long; sepals 2–4, elliptic to obovate, 2.3–2.5 by 1–2.4 mm; stamens 15–20, filaments 1.2–1.5 mm long, whitish to light green, anthers 0.5–0.7 mm long, light yellow. Pistillate inflorescences up to 21 cm long, side branches up to 5.3 cm long; bracts triangular 0.5–1 by 0.5–0.7 mm. Pistillate flowers c. 4 mm in diameter, yellow to red, scented; pedicel 0.4–3 mm long; sepals 3–6, ovate, 1.2–1.8 by 0.5–1.8 mm, yellow-green; ovary 2- or 3-locular, 1.2–1.4 by 1–1.2 mm, pale light green with dark red dots, style 0.4–1 mm long, yellow, stigmas 3.3–5 mm long, pale yellow to brown. Fruits capsules, 8–12 by 6–8 mm, somewhat lobed, dark brown to usually red granular, shortly tomentose; column 3.5–4 mm long. Seeds subellipsoid, 4–4.2 by 4–4.2 by 3.5–3.8 mm, black.

    T h a i l a n d.— NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Lamphun, Lampang, Sukhothai, Phitsanulok, Kamphaeng Phet, Nakhon Sawan; NORTH-EASTERN: Loei, Nakhon Phanom; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Kanchanaburi, Ratchaburi, Phetchaburi, Prachuap Khiri Khan; CENRAL: Saraburi, Nakhon Nayok; SOUTH-EASTERN: Chon Buri, Rayong, Chanthaburi; PENINSULAR: Surat Thani, Phuket, Krabi, Nakhon Si Thammarat, Trang, Songkhla.

    D i s t r i b u t i o n.— From the W. Himalaya and Sri Lanka to Taiwan, throughout Malesia to Australia and W. Pacific.

    E c o l o g y.— Evergreen forest (with much bamboo), dry deciduous (dipterocarp or mixed) forest, secondary growth, very degraded, fireprone agricultural margins, along roadsides, along rocky streams, grassy clearings, near sea shores, mixed Phoenix-Cycas formation; soil: sandy, sandstone, limestone, bedrock quartzite, granite, shale. Altitude: sea level up to 1225 m.

    V e r n a c u l a r.— Kai khat hin (กายขัดหิน), Khi nuea (ขี้เนื้อ) (Chiang Mai); Makai khat (มะกายคัด), (Northern); Kue-bo (กือบอ), Sa-bo-se (ซาบอเส่) (Karen-Mae Hong Son); Tong khao (ทองขาว) (Loei); Khang poi (ขางปอย), Sat pa (ซาดป่า) (Nakhon Phanom); Sak kabuea lawa (สากกะเบือละว้า) (Phitsanulok, Sukhothai); Kham daeng (คำแดง), Kham saet (คำแสด), Thong thuai (ทองทวย), Saet (แสด), Ma khai (มะคาย) (Central); Thaeng thuai (แทงทวย) (Central, Ratchaburi); Lai tua phu (ลายตัวผู้) (Chanthaburi); Cha tri khao (ชาตรีขาว) (Phuket); Phlapphla khi tao (พลับพลาขี้เต่า) (Nakhon Si Thammarat); Khi tao (ขี้เต่า) (Surat Thani); Pla kwang bai yai (พลากวางใบใหญ่) (Trang); Min-ya ma-ya (มินยะมายา) (Malay-Yala); Mue-ra-kae-pu-the (มือราแก้ปูเต๊ะ) (Malay-Narathiwat); Monkey-faced tree, red berry (English).

    U s e s.— Fruits used for red dye. Wood sometimes used for house-posts of medium construction. Fruits and bark, dried and crushed, used medicinally against ‘khai sai dyan’ or ‘ja thai’ in the north.

30. Mallotus pierrei (Gagnep.) Airy Shaw, Kew Bull. 21: 380. 1968; Kew Bull. 26: 304. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 106. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 423. 2007.— Coelodiscus pierrei Gagnep., Not. Syst. 4: 51. 1923.

(Straggling) undershrub, up to 3 m high. Indumentum of stellate and simple hairs, glandular scales yellowish. Stipules triangular, 1.6–5.5 by 0.5–1.1 mm. Leaves opposite; petiole 1.3–15 cm long; blade ovate (to obovate), 2.5–25 by 1.2–15.3 cm, length/width ratio 1.2–2.1, greenish when dry, base caudate to rounded (to cuneate), margin glandularly denticulate, apex acute to acuminate, upper surface somewhat hairy, 1–4 pairs of small extrafloral nectaries on lower palmate nerves, 0.4-0.7 mm in diameter, lower surface densely stellately hairy on venation to subglabrous, a few glandular scales, hair tuft domatia absent, venation (inconspicuously) palmate. Inflorescences axillary to terminal, single, not branching. Staminate inflorescences up to 12 cm long; flowers in well-spaced groups of up to 7 per node; bracts triangular, 1–4 by 0.6–0.7 mm. Staminate flowers 4–7 mm in diameter, yellow; pedicel 3–4 mm long; sepals 4 or 5, elliptic to obovate, 2.5–3.5 by 0.8–1.7 mm; stamens 25–35, filaments 2–3 mm long, whitish, anthers 0.5–0.7 mm long, cream. Pistillate inflorescences up to 8.5 cm long, green, flowers 1–5 per inflorescence; bracts triangular, 1.3–2.4 by c. 0.7 mm; bracteoles conspicuous. Pistillate flowers 2–6.8 mm in diameter; pedicel 1.8–3.5 mm long; sepals 4 or 5, ovate, 2.8–3.2 by 0.4–1.2 mm, green; ovary 3-locular, 1.7–3 by 1.4–2.2 mm, green, covered with stellate hairs and spines, latter subpilose, up to 0.5 mm long; style 0.5–2 mm long; stigmas 1.8–2.3 mm long. Fruits lobed capsules, 10–11 by 7–8 mm, densely (whitish when dry) hairy, dark green, with very dark brown (when dry), strap-like spines; column c. 5 mm long. Seeds subglobular, c. 6.2 by 5.5 by 6 mm.

    T h a i l a n d.— NORTHERN: Chiang Mai (Ban Bo Luang, Doi Kham, Doi Suthep), Lamphun (Mae Li), Lampang (Ngao), Sukhothai (Sa Wang A Rom Temple); NORTH-EASTERN: Loei (Phu Kradueng); SOUTH-WESTERN: Kanchanaburi (Bawngti, Sai Yok), Ratchaburi (Huai Yang), Phetchaburi (Kang Kachan), Prachuap Khiri Khan (Huai Yang, Pak Tawan); PENINSULAR: Chumphon (Khao Talum); Surat Thani (Ban Nai, Khao Phra Rahu, Khirirat Nikhom), Yala (Tarn-tho).

    D i s t r i b u t i o n.— Thailand and Indochina (type).

    E c o l o g y.— Mainly in deciduous forest, also open, often burned areas, scrub jungle, open secondary jungle, and (open, dry) evergreen forest; soil granite, granite-shale bedrock. Altitude: 15–500 m.

    N o t e.— This species is difficult to recognise due to its variability. There is a very distinct geographical cline, the leaves are large and broadly ovate with an often caudate leaf base in the northern provinces. In the north-east the leaves are smaller, but the shape is often the same, though a few leaves have cuneate bases. In the south-west the leaves become much smaller and the shape becomes elliptic with a rounded to almost cuneate leaf base.The leaves are smallest and almost glabrous (in the north quite hairy) in the southern part of the south-west and the northern part of the peninsula, though the peninsula is also the part with the largerst and quite hairy leaves. An extra difficult factor is that young shoots can already flower, they possess very small and usually hairy leaves.

31. Mallotus plicatus (Müll.Arg.) Airy Shaw, Kew Bull. 16: 351. 1963; Bollendorff et al., Blumea 45: 331, fig. 2c, map 1. 2000; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 106. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 424, Fig. 27C. 2007.— [Croton eirocarpoides Wall., Cat. 7728. 1827, nom. nud.].— [Croton castaniofolius Wall., Cat.: 7760. 1847, nom. nud.].— Coccoceras plicatum Müll.Arg., Flora 47: 539. 1864.— Mallotus eriocarpoides Wall. ex Müll.Arg., Linnaea 34: 185. 1865.— Mallotus wallichianus Müll.Arg., Linnaea 34: 196. 1865.— Hymenocardia plicata Kurz, Forest Fl. Brit. Burma 2: 395. 1877.— Coccoceras anisopodum Gagnep., Bull. Soc. Bot. France 71: 1021. 1925.— Mallotus anisopodus (Gagnep.) Airy Shaw, Kew Bull. 16: 351. 1963; Kew Bull. 26: 299. 1972.

Shrubs to trees, up to 15 m high. Indumentum of stellate and simple hairs, orange-red small glandular scales present everywhere. Stipules triangular, 0.7–0.9 by c. 0.3 mm. Leaves alternate to opposite; petiole 1.2–4 cm long; blade elliptic to obovate, 5.5–16 by 2.5–8.5 cm, length/width ratio 1.7–2.8, drying brownish, base slightly emarginate to obtuse, margin (indistinctly) crenate, with glands in sinuses, apex round to bluntly acuminate, upper surface glabrous, basally 1–5 extrafloral nectaries per leaf-side, up to 2.5 by 0.5 mm, apically per leaf side 0–8 circular submarginal extrafloral nectaries on veins, lower surface glabrous, venation triplinerved. Inflorescences axillary and terminal, 1–3 together, unbranched; bracts triangular, 1.2–1.8 by 0.8–1.2 mm. Staminate inflorescences up to 18 cm long; flowers in groups of 3–5(–7). Staminate flowers c. 4 mm in diameter; pedicel c. 2.5 mm long; sepals 3 or 4, ovate to elliptic, 2–3 by 1.4–2 mm, yellow to red-brown; stamens 20–25, filaments 0.5–1.5 mm long, anthers 0.3–0.5 mm long. Pistillate inflorescences 7–21 cm long. Pistillate flowers 3–4 mm in diameter; pedicels 1–3 mm long; sepals 5 or 6, 2–2.5 by 0.3–1 mm; ovary (2)3(4)–locular; stigmas subsessile, 2–2.5 mm long. Fruits obpyramidal, winged, lobed, indehiscent woody capsules, up to 30 by 28 mm, brown,. Seeds subglobose, 4–5 mm in diameter, shiny, dark brown.

    T h a i l a n d.— NORTH-EASTERN: Maha Sarakham (Kosum Phisai); CENTRAL: Saraburi (Mae Nam Sak).

    D i s t r i b u t i o n.— Myanmar (type), Thailand, Laos, Cambodia, Vietnam.

    E c o l o g y.— Evergreen forest. Altitude: c. 150 m.

32. Mallotus repandus (Rottler) Müll.Arg., Linnaea 34: 197. 1865; Hook.f., Fl. Brit. Ind. 5: 442. 1887; Gagnep. in Fl. Gén. I.-C. 5: 365. 1925; Airy Shaw, Kew Bull. 26: 301. 1972; Whitmore, Tree Fl. Mal. 2: 114. 1973; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 107. 2000; S.E.C.Sierra, Welzen & Slik, Blumea 50: 234 fig. 5, map 3. 2005; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 425, Fig. 34. 2007.— Croton repandus (‘repandum’) Rottler, Ges. Naturf. Freunde Berlin Neue Schriften 4: 206. 1803.— Croton rhombifolius Willd., Sp. Pl. 4: 555. 1805.— Helwingia populifolia Spreng., Pl. Pugillus: 89. 1815; Airy Shaw, Kew Bull. 15: 419. 1962.— Rottlera scabrifolia A.Juss., Euph. Gen. Tent.: 111, t. 9, fig. 29B. 1824.— Rottlera viscida Blume, Bijdr.: 608. 1825.— Rottlera scandens Span., Linnaea 15: 348. 1841.— Croton volubilis Llanos, Mem. Real Acad. Ci. Exact. Madrid 4: 503. 1856— Rottlera rhombifolia ( Rottler) Thwaites, En. Pl. Zeyl.: 272. 1861.— Rottlera (?) cordifolia Benth., Fl. Hongk.: 307. 1861.— Mallotus repandus (Rottler) Müll.Arg. var. genuinus Müll.Arg., Linnaea 34: 197. 1865, nom. inval.— Mallotus repandus (Rottler) Müll.Arg. var. scabrifolia (A.Juss.) Müll.Arg., Linnaea 34: 197. 1865.— Mallotus scandens (Span.) Müll.Arg. in DC., Prodr. 15, 2: 982. 1866.— Rottlera repanda (Rottler) Scheff., Ann. Mus. Bot. Lugd.-Bat. 4: 124. 1869.— Mallotus contubernalis Hance, J. Bot. 20: 293. 1882.— Mallotus chrysocarpus Pamp., Nuovo Giorn. Bot. Ital. 17: 413. 1910.— Mallotus contubernalis Hance var. chrysocarpus (Pamp.) Hand.-Mazz., Symb. Sin.: 214. 1931.— Mallotus illudens Croizat, J. Arnold Arb. 19: 146. 1938.— Mallotus repandus (Rottler) Müll.Arg. var. megaphyllus Croizat, J. Arnold Arb. 19: 146. 1938.— Mallotus repandus (Rottler) Müll.Arg. var. chrysocarpus (Pamp.) S.M.Hwang, Acta Phytotax. Sin. 23: 297. 1985.

Scandent shrubs or woody climbers. Indumentum of simple and stellate hairs, glandular scales orange. Stipules early caducous. Leaves alternate; petiole 1–7.7 cm long; blade ovate (to panduriform), 2.8–11.3 by 2.3–9 cm, length/width ratio 1.2–1.3, drying dark green, base rounded to truncate, slightly peltate up to 2 mm, margin entire to somewhat denticulate with few glandular teeth, apex acuminate to cuspidate, upper surface glabrescent, mainly hairy on nerves, with (2)3(4) pairs of black extrafloral nectaries submarginally in lower third, lower surface densely hairy, venation triplinerved. Inflorescences terminal and axillary, single to usually groups of up to 4, not or somewhat branching. Staminate inflorescences up to 20 cm long, side branches up to 9 cm long; flowers in groups of up to 6 per node; bracts triangular, 1.1–1.5 by 0.7–1 mm. Staminate flowers 4–6 mm in diameter, yellowish white to yellow, scented; pedicel 3–3.5 mm long; sepals 3 or 4, elliptic, 2.8–3.2 by 1.1–2 mm; stamens c. 50, filaments 1.8–2.2 mm long, anthers c. 0.6 mm long. Pistillate inflorescences up to 12 cm long; bracts triangular, 1–1.6 by c. 1 mm. Pistillate flowers c. 6 mm in diameter, yellow, scented; pedicel 1(–2 in fruit) mm long; calyx 3- or 4-lobed, c. 3 mm long, lobes ovate, 2.3–2.8 by 1–1.5 mm; ovary 2-locular, 1–1.2 by 1.6–2.4 mm, dull light greenish, densely hairy, no spines; style 0.3–0.4 mm long, brown; stigmas 3–4 mm long, brown. Fruits lobed capsules, c. 9.5 by 5 mm, densely hairy, without spines; column 2–3 mm long. Seeds not seen.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Chiang Dao), Chiang Rai (Doi Luang), Phrae (Hue Kamui); NORTH-EASTERN: Loei (Phu Luang), Khon Kaen (Pha Bhraung Cave); EASTERN: Nakhon Ratchasima (Puk Thongchai); SOUTH-WESTERN: Kanchanaburi (Sangkhla Buri), Ratchaburi (Ban Pong), Prachuap Khiri Khan (Pranburi); CENTRAL: Saraburi (Sam Lan), Bangkok (Wat Sing); SOUTH-EASTERN: Sa Kaeo (Wattana), Chon Buri (Siracha, Tong Brong), Chachoengsao; PENINSULAR: Surat Thani (Ko Nong, Ko Samui), Yala (Be Tong).

    D i s t r i b u t i o n.— -W. Peninsular India (type?), Sri Lanka to Taiwan and the Philippines, scattered throughout Malesia (absent from Borneo) to Australia and New Caledonia.

    E c o l o g y.— Usually in disturbed places like thickets, along roads, along streams in evergreen and especially mixed deciduous forest; soil: calcareous, limestone bedrock. Altitude: 150–550 m.

    V e r n a c u l a r.— Makai khruea (มะกายเครือ), Mapop khruea (มะปอบเครือ) (Northern); Pho khan (โพคาน) (Chai Nat); Kurapia (กุระเปี้ยะ) (Pattani); Naeo nam (แนวน้ำ) (Prachuap Khiri Khan); Yiao maeo thao (เยี่ยวแมวเถา) (Narathiwat); Yiao maeo (เยี่ยวแมว) (Peninsular); Ku-ko-bue-ya (กูเก๊าะบือยะ), Ku-ko-mu-ya (กูเก๊าะมูยะ) (Malay-Narathiwat).

33. Mallotus resinosus (Blanco) Merr., Sp. Blanc.: 222. 1918; Enum. Philipp. 2: 436. 1923; Airy Shaw, Kew Bull. 26: 294. 1972; Airy Shaw, Kew Bull. Add. Ser. 4: 161. 1975; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 427, Fig. 35. 2007.— Adelia resinosa Blanco, Fl. Filip. ed. 2: 562. 1845.— Claoxylon muricatum Wight, Icon. 5, 2: 24, t. 1886. 1852.— Axenfeldia intermedia Baill., Ét. Gén. Euphorb.: 419. 1858.— Rottlera muricata (Wight) Thwaites, Enum. Pl. Zeyl.: 273. 1864.— Mallotus dispar (Blume) Müll.Arg. var. psiloneurus Müll.Arg., Linnaea 34: 191. 1865.— Mallotus muricatus (Wight) Müll.Arg., Linnaea 34: 191. 1865.— Coelodiscus muricatus (Wight) Gagnep. in Lecomte, Fl. Indo-Chine 5: 369, p.p.. 1925.— Mallotus spec. nov. 2; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 110. 2000.— Mallotus viridis Welzen & Chayam., Kew Bull. 56: 652 2001.

Shrubs to trees, up to 6 m high. Indumentum almost absent, few simple and stellate hairs, many glandular whitish scales on most parts. Stipules triangular, c. 2.3 by 1.1 mm. Leaves opposite; petiole 0.2–1.3 cm long; blades elliptic to slightly obovate, 5.2–16.5 by 2.3–8 cm, length/width ratio 2.1–2.3, drying greenish, base narrowly emarginate, margin crenulate to subentire to denticulate with glandular teeth, apex bluntly acuminate, upper surface glabrous, 2 or 3 large extrafloral nectaries near base, close to midrib, 1–1.2 by c. 0.8 mm, lower surface glabrous, with many glandular scales, domatia absent, venation penninerved. Inflorescences terminal or axillary, single, not branched. Staminate inflorescences only seen in very young stage, c. 3 flowers per node; bracts triangular, c. 1.3 by 1.3 mm; sepals 4; stamens c. 50. Pistillate inflorescences up to 6.3 cm long; bracts triangular, c. 1.3 by 1.3 mm. Pistillate flowers c. 3 mm in diameter (excluding spines); pedicel c. 2.5 mm long; sepals 6, ovate, c. 1.8 by 0.8 mm, subglabrous; ovary 3-locular, c. 2.2 by 3 mm, densely set with glandular scales except for the strong, up to 2 mm long spines; style c. 1.3 mm long; stigmas c. 2.2 mm long. Fruits lobed capsules, c. 13 by 7.5–9 mm, yellowish green, set with glandular scales, few spines up to 2 mm long; column 4.5–5 mm long. Seeds subglobose, c. 6 by 5.2 by 5.5 mm.

    T h a i l a n d.— SOUTH-EASTERN: Chanthaburi (type of M. viridis: Soi Dao Nua, Chanthaburi, SANTISUK 6684, BKF holoSoi Dao Nua); PENINSULAR: Ranong (Khao Tala); Surat Thani (Ko Samui); Phuket (Ao Sane Beach).

    D i s t r i b u t i o n.— S. India, Sri Lanka, Andman & Nicobar Islands, Thailand, Laos, Vietnam, Philippines, Borneo, Java, Sulawesi, Lesser Sunda Islands, Moluccas, Papua New Guinea, and NE Australia.

    E c o l o g y.— Uncommon in secondary evergreen forest by roadside to evergreen forest; soil: recorded once from limestone. Altitude: 0–350 m.

34. Mallotus subcuneatus (Gage) Airy Shaw, Kew Bull. 26: 304. 1972; Whitmore, Tree Fl. Mal. 2: 115. 1973; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 109. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 429. 2007.— Coelodiscus subcuneatus Gage, Rec. Bot. Surv. Ind. 9: 240. 1922.— Coelodiscus dispar sensu Airy Shaw, Kew Bull. 21: 380. 1968, non Kurz (1873).

Shrubs to trees, up to 5 m high. Indumentum of simple and stellate hairs, glandular scales orangish. Stipules ovate, 3–5 by c. 1.2 mm. Leaves opposite; petiole 0.6–4 cm long; blade ovate, 8–17.5 by 3.5–8 cm, length/width ratio 2.2–2.3, drying greenish to brownish, base rounded, margin (sub)entire with a few very indistict glandular teeth, apex cuspidate, upper surface glabrous, at least a basal pair of small round extrafloral nectaries to up to 7 submarginally per side, all below basal nerves; lower surface densely hairy on venation, many glandular scales, venation triplinerved. Inflorescences terminal or axillary, single, very short, not branching. Staminate inflorescences racemes, up to 1.5 cm long; flowers at least up to 4 per node; bracts triangular, c. 2.5 by 1 mm. Staminate flowers c. 4 mm in diameter; pedicel short; sepals 3, ovate, 2.8–3 by c. 1.2 mm; stamens c. 40, filaments 2.2–3 mm long; anthers c. 0.2 mm long. Pistillate inflorescences terminally, umbelliform, usually with an extra flower halfway, up to 7.8 cm long; flowers up to 4 per umbel; bracts triangular 2–2.2 by 0.8–1.5 mm. Pistillate flowers c. 5.2 mm in diameter; pedicel 3.2(–54 in fruit) mm long; sepals 3, ovate, c. 4 by 1.2 mm; ovary 3(4)-locular, c. 3 by 3.5 mm, densely set with spines of up to 1.3 mm long; style c. 2.5 mm long; stigmas c. 2.5 mm long. Fruits lobed capsules, c. 15 by 8 mm, densely hairy, green, spines strap-like, not very dense, up to 1.2 mm long; column c. 5.5 mm long. Seeds subglobose, 6–7 by 5.2–6 by 5–6 mm.

    T h a i l a n d.— PENINSULAR: Surat Thani (Ko Samui), Phuket (Kamala), Krabi (Ko Lanta).

    D i s t r i b u t i o n.— Thailand and Peninsular Malaysia (type).

    E c o l o g y.— Locally common (by streams) in evergreen forest. Altitude: 100–300 m.

35. Mallotus tetracoccus (Roxb.) Kurz, J. Asiat. Soc. Bengal 62: 245. 1873; Alston in Trimen, Handb. Fl. Ceylon 6: 267. 1931; Croizat, J. Arnold Arbor. 21: 503. 1940; Philcox in Dassan., Revis Handb. Fl. Ceylon 11: 153. 1997; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 433. 2007.— Rottlera tetracocca Roxb. [Hort. Beng.: 73. 1814, nomen nudum] Fl. Ind. 3: 826. 1832.— Mallotus albus auct. non (Roxb.) Müll.Arg.: Müll.Arg., Linnaea 34: 188. 1865; Hook.f., Fl. Brit. Ind. 5: 429.1887; Trimen, Handb. Fl. Ceylon 4: 64. 1898; all p.p.: Rottlera tetracocca, Thwaites CP 2118.— Rottlera peltata auct. non Roxb. (= Mallotus roxburghianus Müll.Arg.): Wight, Icon. Pl. Ind. Orient. 5: 21, t. 1873. 1852.— Mallotus albus (Roxb.) Müll.Arg. var. occidentalis Hook.f., Fl. Brit. Ind. 5: 429. 1887.— Mallotus mollissimus auct. non (Geiseler) Airy Shaw: Airy Shaw, Kew Bull. 26: 297. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 102. 2000, both p.p. (see note under M. metcalfianus).

Shrubs to treelets, up to 20 m high, d.b.h. up to 30 cm. Outer bark pale creamy brown to orange brown, smooth with scattered lenticels and very shallow vertical fissures, c. 0.5 mm thick; inner bark 3-5 mm thick, dirty white, outside green. Indumentum tomentose, shorter stellate hairs yellowish, larger ones (partly) brownish, glandular scales orange. Stipules triangular, c. 1.5 by 0.8-1 mm, early caducous. Leaves alternate to usually opposite beneath inflorescences; petiole 4.7-8 cm long, often grooved when dry; blades triangular to ovate, 8-25.5 by 10-19.5 cm, length/width ratio 0.9-1.3, drying (light or greenish) brownish, base emarginate to rounded, not to up to 8 mm peltate, margin laxly serrulate to serrate above largest width, apex acuminate to cuspidate, upper surface dark green, basally hairy on major nerves, extrafloral nectaries seldom absent, usually several near insertion, elliptic, 1.2-2 by 0.7-1 mm, sometimes confluent, often several further away on basal nerve, often few to many submarginally in upper half, lower surface greenish white to rusty brown, densely tomentose, epidermis not visible, glandular scales usually visible, domatia absent, venation palmate, 7-9 nerves along midrib on each side. Inflorescences terminal panicles, very sturdy, branches more than 1 mm thick, up to 35 cm long; bracts triangular, thick, in staminate inflorescences 0.8-1.6 by 0.8-1.3 mm, in pistillate ones c. 1.5 by 2.5 mm; bracteoles absent. Staminate flowers 3.5-5 mm in diameter, dull yellowish (green); buds brown; pedicel 1.8-5 mm long, yellowish green; sepals (2-)4-5(6), ovate to elliptic, 2.7-3.5 by 0.8-2 mm, reflexed; stamens 45-65, filaments 2-2.6 mm long, pale greene, anthers c. 0.3 by 0.7 mm, yellow. Pistillate flowers 3.5-4.7 mm in diameter, subsessile, sweet-scented; calyx 3- or 4-partite, urceolate, 3-4 mm high; ovary (3)4(5)-locular, 1.5-2 by 2-2.5 mm, covered with soft spines, style c. 0.5 mm high, broad; stigmas recurved, 1.5-2.2 mm long, with long lemon-yellow papillae above. Fruits lobed rhegmas, 12-14 mm by 8-10 mm high, white when young, later yellowish brown, covered with c. 100 stout, up to 3 mm long, tomentose spines; wall thin. Seed subobovoid, c. 6 by 4-5 by 4-4.2 mm, blackish, warty, without aril.

    T h a i l a n d.— NORTHERN: Chiang Rai (Payapri (Akha tribe) village).

    D i s t r i b u t i o n.— Sri Lanka, India, Bangladesh, Thailand, China (Yunnan). Probably also present in Myanmar.

    E c o l o g y.— Pioneer species found in disturbed evergreen forest, sometimes mixed with deciduous elements, along roadsides, in thickets in cultivated areas, garden boundaries and secondary forest; bedrock granite. Altitude: sea level up to 1600 m.

    N o t e.— See also note under Mallotus metcalfianus. Mallotus barbatus, M. metcalfianus, M. macrostachyus, M. paniculatus, and M. tetracoccus can easily be confused. They are easiest to recognise when in fruit. (Relatively) few and short stout spines are found in M. paniculatus and M. tetracoccus; M. tetracoccus has more spines (c. 100), and more sturdy inflorescences (branches more than 1 mm thick, less so in M. paniculatus). Many long and slender spines are found in M. barbatus, M. metcalfianus, and M. macrostachyus. Of these three M. metcalfianus has the lowest number of spines, they are indivually visible, the latter is not the case in the other two species. The leaves of M. metcalfianus are also more densely hairy (epidermis not visible) and domatia are lacking. Mallotus barbatus has distinctly peltate leaves with no domatia, while in M. macrostachyus the leaves are subpeltate and possess domatia.

36. Mallotus thorelii Gagnep., Not. Syst. 4: 53. 1923; in Fl. Gén. I.-C. 5: 358. 1926; Airy Shaw, Kew Bull. 26: 307. 1972; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 110. 2000; Slik & Welzen, Blumea 46: 47, Fig. 18, Map 6. 2001; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 434, Fig. 38. 2007.

Straggling shrubs to trees, up to 10 m high, smelling of fenucreek. Indumentum of simple and stellate hairs, glandular scales orangish. Stipules triangular, 2.5–4.5 by 0.9–1.4 mm. Leaves terminally grouped, alternate to subopposite; petiole 1.5–13 cm long; blade ovate, 3–16 by 2.2–7.7 cm, length/width ratio 1.2–1.6, drying greenish to bownish, base slightly emarginate, rounded, not to peltate by up to 2 cm, margin subentire with few small glandular teeth, apex acuminate to cuspidate, upper surface with glandular scales, especially near insertion, 2–6 small, black extrafloral nectaries in peltate part, 0.3–0.7 mm in diameter, apically 0–3 extrafloral nectaries; lower surface with stellate and simple hairs on venation, many glandular scales, hair tuft domatia usually present; venation palmate. Inflorescences terminal to axillary, single (to seldom few together), unbranched. Staminate inflorescences up to 11 cm long; flowers in groups of up to 7 per node; bracts ovate to elliptic, 1.5–2.8 by 0.5–1.2 mm. Staminate flowers c. 3.5 mm in diameter; pedicel 1.3–2.3 mm long; sepals 4 or 5, elliptic, 2–2.5 by 0.5–1.1 mm; stamens 40–50, filaments 1.2–1.8 mm long; anthers 0.3–0.5 mm long. Pistillate inflorescences up to 14.5 cm long; bracts triangular, 3.5–3.8 by c. 1.3 mm. Pistillate flowers: pedicel 1–1.5 mm long; sepals 2–5, ovate to triangular, 1.3–3.5 by 0.7–2.8 mm; ovary 3(4)-locular, echinate with 1 mm long spines, densely woolly hairy; style 0.6–1.5 mm long; stigmas 2–4 mm long. Fruits lobed capsules, 6–8 by 5–6 mm, pale green, rather densely echinate or verrucose, shortly grey-tomentellous; column c. 4 mm high. Seeds subglobular, c. 2.5 by 2 by 1.8 mm.

    T h a i l a n d.— NORTHERN: Nakhon Sawan; EASTERN: Nakhon Ratchasima (Ta Chang), Surin (Tathum), Si Sa Ket (Kantralak); SOUTH-WESTERN: Phetchaburi; CENTRAL: Saraburi (Menam Sak); SOUTH-EASTERN: Sa Kaeo (Lam Nang Rong), Prachin Buri (Aranya Prathet). Seemingly also in North-eastern, Eastern, and Central.

    D i s t r i b u t i o n.— Thailand, Laos, Cambodia, Vietnam (type).

    E c o l o g y.— Mixed or evergreen forest or scrub, at low altitudes.

    V e r n a c u l a r.— Fai nam (ฝ่ายน้ำ) (North-eastern).

37. Mallotus tiliifolius (Blume) Müll.Arg., Linnaea 34: 190. 1865; in DC., Prodr. 15, 2: . 1866; Airy Shaw, Kew Bull. 26: 305. 1972; Whitmore, Tree Fl. Mal. 2: 114. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 170. 1975; Welzen, Slik & Bollendorff in Welzen et al., Thai For. Bull. (Bot.) 28: 110. 2000; Welzen, S.E.C.Sierra, Slik & Bollendorff in Welzen & Chayam., Fl. Thailand 8, 2: 436. 2007.— Halecus litora Rumph., Herb. Amboin. 3: 196, t. 126. 1743, nom. inval.— Croton tiliifolius Lam. var. aromaticus auct. non (L.) Lam.: Lam., Encycl. 2: 206. 1786, p.p., pro Halecus litorea.— Croton acuminatum Lam., Encycl. 2: 207. 1786 (non Mallotus acuminatus Müll.Arg.).— Rottlera acuminata (Lam.) A.Juss., Euphorb. Gen. Tent.: 33. 1824— Rottlera tiliifolia Blume (‘tiliaefolia’), Bijdr.: 607. 1825.— Rottlera blumei Decne., Nouv. Arch. Mus. [Paris] 3: 486. 1835, nom. superfl.— Adelia papillaris Blanco, Fl. Filip., ed. 2: 562. 1845.— Mallotus zollingeri auct. non Müll.Arg.: Fern.-Vill. in Blanco, Fl. Filip. (ed. 3): 195. 1880.— Mallotus playfairii Hemsl., J. Linn. Soc. 26: 441. 1894.— Croton enantiophyllus K.Schum. in K.Schum. & Lauterb. Nachtr. Fl. Schutzgeb. Südsee: 296. 1905.— Mallotus papillaris (Blanco) Merr., Philipp. J. Sci. Bot. 7: 238. 1912; Sp. Blancoan.: 434. 1923.— Mallotus palauensis Hosok., Trans. Nat. Hist. Soc. Formosa 25: 25. 1935.

(Straggling) shrubs to trees, up to 7.5 m high. Indumentum of dense, small stellate hairs, simple hairs seemingly absent; glandular scales orangish. Stipules early caducous. Leaves opposite; petiole 1.3–6 cm long; blade ovate, 4.4–14 by 3.8–12 cm, length/width ratio c. 1.2, drying greenish brown, base emarginate to truncate, margin subentire with small glandular teeth, apex cuspidate to caudate, upper surface subglabrous except for midrib, basally near insertion 1 or 2 extrafloral nectariess on each side below main nerves, lower surface densely tomentose, whitish, many glandular scales, no pockets, venation palmate. Inflorescences terminally to axillary, single, not branching; bracts triangular, 1–1.2 by 0.5–0.7 mm. Staminate inflorescences up to 12 cm long; flowers in groups of up to 8 per node. Staminate flowers 4.3–5.1 mm in diameter, yellow, strongly scented; pedicel 2–3.2 mm long; sepals 4 or 5, ovate to elliptic, 2.5–2.8 by 0.9–1.1 mm; stamens over 100, filaments c. 2.2 mm long; anthers c. 0.3 mm long. Pistillate inflorescences up to 7 cm long. Pistillate flowers c. 4 mm in diameter; pedicel c. 1.7 mm long; sepals 4 or 5, c. 2.2 by 0.7 mm; ovary 3-locular, c. 1 by 1.2 mm, indistinctly armed; style c. 0.4 mm long; stigmas c. 4 mm long. Fruits lobed capsules c. 15 by 7 mm, softly echinate with short spines; column not seen. Seeds subglobose, 5–7.5 mm in diameter.

    T h a i l a n d.— PENINSULAR: Surat Thani (Kanchanadit, Ko Prap, Ko Samui).

    D i s t r i b u t i o n.— Thailand, Taiwan, Hainan, throughout Malesia to N. Australia and the W. Pacific to Fiji.

    E c o l o g y.— In scrubs, edge of evergreen forest or edge of tidal marsh, in littoral or close to sea.

    N o t e.— The nomenclature of this species is extremely complicated, because Müller Argoviensis in his 1865 publication refers to the names Croton tiliifolius Lam., Rottlera tiliifolia Blume, and Rottlera acuminata A.Juss. Müller did not clarify on which tiliifolius he based his new combination. At first sight it should be the oldest and first mentioned epithet, the epithet of Lamarck, which is a real Croton and not Mallotus. If this would be correct, then the name of this taxon has to change completely. However, in his more elaborate publication of 1866 Müller shows that Mallotus tiliifolius includes the β variety of Croton tiliifolius Lam. (he accepts the other variety as the true Croton tiliifolius). (In fact this β variety, called aromaticus, is also a true Croton, C. aromaticum, and only the included pre-Linnean name of Rumphius, Haleca litorea, is really M. tiliifolius.) Thus it can be deduced that Müller based his new combination on the name of Blume and, fortunately, this means no name change for this taxon.

    In fact the epithet acuminatus is also older than Blume’s epithet, because it is based on Croton acuminatum Lamarck (A. de Jussieu based his Rottlera acuminata on this species). However, Müller already made an earlier combination Mallotus acuminatus and this means that the epithet is not any longer available for use within Mallotus and tiliifolius then is the oldest epithet.

38. Mallotus tokiae Welzen

Shrub, ca. 1.5 m high, probably dioecious. Indumentum of stellate to almost lepidote hairs, glandular scales lacking. Stipules triangular, 4.2—6 by 1.2—2.1 mm, outside hairy, inside glabrous, late caduceus. Leaves opposite; petiole 5—9 mm long, densely hairy, completely pulvinate; blade elliptic, 13—26.7 by 4.3—9.4 cm, length/width ratio 2.8—3, drying greenish brown, coriaceous, base cuneate to narrowly emarginated, margin entire, apex bluntly acute, upper surface glabrous, with extra floral nectaries, elliptic, c. 0.8 by 0.4 mm, on every major nerve, c. 0.5-1 cm from the margin, except the third nerve, there present above the nerve, becoming smaller and disappearing towards the apex, lower surface subglabrous with few stellate hairs, lacking peltate scales; venation penninerved, hardly visible from above and beneath, nerves 8—14, looped and closed near margin, somewhat bullate within the arches. Staminate inflorescences and staminate and pistillate flowers unknown. Fruits terminal, single, axillary, lobed capsules surrounded by bracts, presumably 3-locular, already dehisced, probably about 2 by 1 cm, opening septicidally and incompletely loculically from the base leaving paired valves, valves outside greenish, densely stellately hairy and covered with very slender, up to 2 mm long spines with an acute, bent apex; pedicel c. 5 mm long, densely hairy; sepals persistent, 5, ovate, c. 5.2—5.5 by c. 3 mm, valvate, reflexed, outside hairy, inside glabrous, margin entire, apex rounded; disc absent; wall thin, woody when dry; columella up to 8 mm long, sturdy, apically broadened. Seeds subellipsoid, 9.5—10 by c. 8.5 by 8—8.2 mm, without arilloid.

    T h a i l a n d.— PENINSULAR: Surat Thani (Ratchaprapha Dam, Chayam., POOMA, CHAMCHUMROON, PHATTARAHIRANKANOK & MIDDLETON 2580, holo in BKF, iso in BKF).

    D i s t r i b u t i o n.— Endemic in Thailand.

    E c o l o g y.— Scattered in evergreen forest on limestone bedrock. Altitude: c. 100 m. Fruiting: February.

    E t y m o l o g y.— The species is named in honour of Nannapat Pattharahirantricin, who is nicknamed Tok. She is one of the collectors (then still called K. Phattarahirankanok) and an invaluable staff member of the Forest Herbarium in Bangkok.

    C o n s e r v a t i o n.— According to the IUCN criteria (2001), this species is DD (Data Deficient), because no other specimens are known and information is lacking.

    N o t e.— 1. The species is only known from one fruiting specimen.