Flora of Thailand Euphorbiaceae

 

26. Cleistanthus

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Genus description

Identification key

Species descriptions

Cleistanthus

Hook.f. ex Planch., Hook. Icon. Pl. 8: tab. 779. 1848; Müll.Arg. in DC., Prodr. 15, 2: 503. 1866; Jabl. in Engl., Pflanzenr. IV.147.viii: 8. 1915; G.L.Webster, Ann. Missouri Bot. Gard. 81: 38. 1994; S.Dressler, Blumea 44: 111. 1999; Radcl.-Sm., Gen. Euphorbiacearum: 18. 2001; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 167. 2005; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 71. 2014.— Nanopetalum Hassk., Verslagen Meded. Afd. Natuurk. Kon. Akad. Wetensch. 4: 140. 1855.— Lebidiera Baill., Étude Euphorb.: 50. t. xxvii.1, 3–4. 1858.— Stenonia Baill., Étude Euphorb.: 578, t. xxii: 2–5. 1858 (non Didr. nec Endl.). — Leiopyxis Miq., Fl. Ned. Ind., Eerste Bijv.: 445. 1861.— Lebidieropsis Müll.Arg., Linnaea 32: 79. 1863.— Kaluhaburunghos Kuntze, Revis. Gen. Pl.: 607. 1891, nom. illeg.— Stenoniella Kuntze in T.Post & Kuntze, Lex. Gen. Phan: 535. 1903.— Schistostigma Lauterb., Fl. Schutzgeb. Südsee, Nachtr.: 299. 1905.— Zenkerodendron Gilg ex Jabl. in Engl., Pflanzenr. IV.147.viii: 7. 1915, nom. nud.— Godefroya Gagnep., Bull. Soc. Bot. France 70: 435. 1923.— Paracleisthus Gagnep., Bull. Soc. Bot. France 70: 449. 1923.

Shrubs to big trees, monoecious (to dioecious). Indumentum simple hairs. Stipules small. Leaves alternate, simple; petiole short, with transverse cracks when dry; blade eglandular, margin entire, drying greenish to brownish, usually rather shiny above, penninerved. Flowers in usually bisexual fascicles, (ramiflorous or) in axils of usually smaller leaves, sometimes pseudo-racemose when on leafless branches, glomerules multibracteate. Flowers symmetric, sessile to pedicellate; calyx 5-lobed, lobes valvate; petals 5, smaller than sepals; disc annular. Staminate flowers: stamens 5, filaments basally connate with extending pistillode, anthers basifixed, introrse; pistillode 3-lobed. Pistillate flowers: disc divided into an outer annulus and usually inner cupuliform or conical part, glabrous; ovary 3-locular (Thailand); ovules 2 per locule; style short, stigmas 2-lobed. Fruits capsular, 3-lobed to subglobose, smooth, stipitate or not, dehiscing into 2-valved cocci leaving basal part of testa and columella. Seeds trigonoid to ellipsoid, exarillate, smooth.

    A genus of over 100 species, distributed in Africa and in Asia from India to Melanesia. 15 species in Thailand. Classification: subfamily Phyllanthoideae, tribe Bridelieae.

Key to the species

(based mainly on pistillate flowers)

1. Cleistanthus decurrens Hook.f., Fl. Brit. Ind. 5: 278. 1887, Ridl., Fl. Mal. Pen. 3: 191. 1924; Airy Shaw, Kew Bull. 26: 236. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; Chin, Limest. Fl. Mal. 1: 228. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; S.Dressler, Blumea 44: 117. 1999; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 169. 2005.— Cleistanthus mattangensis Jabl. in Engl., Pflanzenr. IV.147.viii: 33. 1915.

Shrubs or small trees, up to 5 m high; bark yellowish grey, young branches brown hairy, glabrescent. Stipules triangular, 1–1.5 by 1.5–2 mm, glabrous. Leaves: petiole 0.4–0.5 cm long, slightly square in cross section, pubescent when young, glabrescent; blade elliptic, obovate or oblong-obovate, 3–15 by 2–7 cm, chartaceous to coriaceous, base attenuate, apex acute or acuminate, whitish hairy when young, glabrescent; nerves 7–9 pairs, inconspicuous, midrib prominent. Flowers axillary or on leafless branches, subsessile; bracts ovate, 1.5–3 by 1–1.5 mm, hairy outside. Staminate flowers: sepals ovate, 1–1.5 by 1.5–2 mm, apex acute, glabrous or hairy; petals spathulate, 0.5–0.8 by c. 1 mm, margin irregularly lobed, glabrous; disc disciform; stamens with ovate anthers; pistillode cylindrical, lobe apex obtuse, glabrous. Pistillate flowers: sepals elliptic, c. 2.5 by 1 mm, acute, hairy; petals spathulate or linear, c. 1 by 0.5 mm, glabrous or hairy at the apex; disc cup-shaped, margin irregularly lobed or nearly entire; ovary hirsute. Fruits not stipitate or stipe up to 6 mm long, about 1 cm in diameter, slightly hairy, sometimes only along furrows or at the base, black when mature.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan; SOUTH-EASTERN: Chon Buri.

    D i s t r i b u t i o n.— Malay Peninsula (type), Borneo, Philippines, Lesser Sunda Islands.

    E c o l o g y.— In evergreen forest. Altitude: c. 200 m. Flowering in March; fruiting in March and June.

    V e r n a c u l a r.— Nok non kan khrip (นกนอนก้านครีบ) (General).

2. Cleistanthus denudatus Airy Shaw, Kew Bull. 21: 367. 1968; Kew Bull. 26: 236. 1972; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 169. 2005.

Shrubs, up to 4 m high; branches furrowed, brown hairy when young, glabrescent. Stipules triangular or flagelliform, c. 2.5 by 1.2 mm, glabrous. Leaves: petiole 0.4–0.5 cm long, glabrous; blade broadly ovate or elliptic, (2–)3.5–10.5 by (0.5–)1.5–3.5 cm, chartaceous to coriaceous, base cuneate, apex obtuse or acute to acuminate, glabrous; nerves 9(–11) pairs, conspicuous beneath. Flowers axillary; yellowish, sessile; bracts ovate, c. 0.8 by 1.5 mm, hairy. Staminate flowers: not seen. Pistillate flowers: sepals ovate, glabrous; petals spathulate, glabrous; disc cup-shaped outside, urceolate inside, enveloping the ovary, ovary glabrous. Fruits about 5 mm in diameter, not stipitate, brown when mature, glabrous.

    T h a i l a n d.— NORTHERN: Lampang; SOUTH-WESTERN: Prachuap Khiri Khan (Pranburi, type: AMNUAY s.n., K n.v.); CENTRAL: Saraburi; SOUTH-EASTERN: Rayong; PENINSULAR: Satun.

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

    E c o l o g y.— In evergreen forest, over sandstone. Altitude: c. 280 m. Flowering in September–February; fruiting in June.

    V e r n a c u l a r.— Tin pae (ตีนแป) (Lampang); phan ta (พันตา) (Central).

3. Cleistanthus glandulosus Jabl. in Engl. Pflanzenr. IV.147.viii: 18. 1915; Ridl., Fl. Mal. Pen. 3: 189. 1924; Whitmore, Tree Fl. Malaya 2: 81. 1973; Airy Shaw, Kew Bull. 32: 72. 1977; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 170, fig. 37. 2005.

Shrubs or small trees; bark grooved; young branches brown hairy, glabrescent. Stipules triangular, c. 2 by 0.8–1 mm, subglabrous or slightly hairy. Leaves: petiole 0.3–0.4 cm long, slightly pubescent; blade elliptic or elliptic-oblong, 4–10 by 2.5–5 cm, subcoriaceous, base cordate or subobtuse, apex acuminate, glabrous above except at base, densely tomentose beneath, especially on midrib, reddish purple when dry; nerves 11 or 12 pairs, conspicuous. Flowers axillary or along leafless branches or branches with small subglobular leaves of c. 0.5 by 0.5–0.6 cm; bracts triangular, 1–2 by 0.5–1.5 mm, densely hairy. Staminate flowers pedicellate; sepals apex acuminate, hairy; petals fan-shaped, glabrous; disc cup-shaped, with 10-deep lobes; stamens with ovate anthers; pistillode apex truncate, hairy. Pistillate flowers: ovary hairy. Fruits not seen.

    T h a i l a n d.— PENINSULAR: Narathiwat.

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

    E c o l o g y.— In evergreen forest. Altitude: 300–400 m. Flowering in March.

4. Cleistanthus gracilis Hook.f., Fl. Brit. Ind. 5: 277. 1887; Ridl., Fl. Mal. Pen. 3: 190. 1924; Airy Shaw, Kew Bull. 26: 236. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 170. 2005.— Cleistanthus dasyphyllus F.N.Williams, Bull. Herb. Boiss., sér. 2, 5: 31. 1905.

Shrubs or small to medium-sized trees, up to 8 m high; bark grooved, glabrous or minutely hairy when young. Stipules triangular, c. 1.2 by 1 mm, glabrous, margin with irregular lobes. Leaves: petiole 0.2–0.4(–0.5) cm long, glabrous; blade ovate to elliptic, 2.5–6(–7.5) by 0.7–3.5 cm, subcoriaceous, base cuneate or subobtuse, apex caudate up to 3 cm long, glabrous, dark green above, glaucous or not beneath; nerves 4–7 pairs, obscure, midrib conspicuous. Flowers axillary or along branches with small leaves or on leafless branches, supported by many bracts; whitish green, sessile; bracts triangular or pentangular, 0.1–0.5 by 0.1–0.3 mm, acute, hairy inside and along margin. Staminate flowers 4–5 mm in diameter; sepals oblong, c. 3 by 1 mm, margin fimbriate, lobes acute, glabrous or minutely hairy at apex; petals fan-shaped, c. 1 by 1 mm, margin irregularly serrate, glabrous; disc cup-shaped, margin flattened, with irregular lobes, veined; anthers ovate-oblong; pistillode glabrous. Pistillate flowers 4–5 mm in diameter; sepals elliptic-oblong, 1.5–2 by 1.3–1.5 mm, glabrous; petals fan-shaped or linear, c. 0.5 by 0.1 mm, glabrous; disc outside cup-shaped, the inner part cylindrical, margin nearly entire, enveloping the ovary; ovary nearly globose, 1–2 by 0.5–1 mm, hirsute. Fruits sessile, with 1–2 seeds per locule, slightly hirsute, densely so at base, red when mature. Seeds trigonal in transverse section.

    T h a i l a n d.— SOUTH-WESTERN: Ratchaburi, Prachuap Khiri Khan; PENINSULAR: Phangnga, Krabi, Nakhon Si Thammarat, Phatthalung, Songkhla, Narathiwat.

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

    E c o l o g y.— In dry evergreen forest, over limestone. Altitude: c. 500 m; Flowering: February–April; fruiting: March–August.

    V e r n a c u l a r.— Sam phan ta (สามพันตา) (Ratchaburi).

5. Cleistanthus helferi Hook.f., Fl. Brit. Ind. 5: 280. 1887; Jabl. in Engl., Pflanzenr. IV.147.viii: 81. 1915; Ridl., Fl. Mal. Pen. 3: 191. 1967; Airy Shaw, Kew Bull. 26: 236. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 172, plate IX: 4. 2005.

Shrubs to medium-sized trees, up to 10 m high; bark brown, with small grooves, hirsute when young, glabrescent. Stipules triangular, 5–6 by (1–)1.5 mm, apex acuminate, hairy along the margin. Leaves: petiole 0.3–0.5 cm long, densely hairy; blade oblong to ovate-oblong or obovate-elliptic, 2–17.5 by 1–4(–9) cm, chartaceous or coriaceous, base obtuse, apex acute to acuminate, above hairy on the midrib, sparsely hairy beneath and especially hirsute on the midrib; midrib conspicuous above, nerves 8–12 pairs, obscure above, more conspicuous beneath. Flowers axillary, 1–6 per fascicle, whitish green, sessile; bracts obovate or subglobular, 3–4 by 1.5–2 mm, densely hairy outside, glabrous inside. Staminate flowers c. 7 mm in diameter; sepals elliptic, 3.5–11 by 1.5–3 mm, densely hairy outside; petals membraneous, fan-shaped, or deeply 2–3-lobed, 1.3–1.5 by 1–1.2 mm, margin irregularly 4- or 5-lobed, with visible veins, glabrous or rarely hairy; disc funnel-shaped, margin thick or cushion-shaped, irregularly 4- or 5-lobed; stamens with triangular androphore, 2.5 by 0.2–0.5 mm, anthers obovate-oblong; pistillode lobes acuminate, glabrous. Pistillate flowers: sepals ovate-oblong; petals ovate-rhomboid, margin irregularly serrate; ovary with dense hairs. Fruits hairy, brown when mature.

    T h a i l a n d.— SOUTH-EASTERN: Chon Buri; PENINSULAR: Chumphon, Ranong, Phangnga, Phuket, Yala.

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

    E c o l o g y.— In hill evergreen forest, lowland evergreen forest and open areas on the beach. Altitude: up to 1,000 m. Flowering: November–June; fruiting: November–May.

    V e r n a c u l a r.— Nok non (นกนอน) (Yala).

6. Cleistanthus hirsutopetalus Gage, Bull. Misc. Inform. Kew 1914: 239. 1914; Ridl., Fl. Mal. Pen. 3: 190. 1924; Whitmore, Tree Fl. Malaya 2: 79. 1973; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 172. 2005.

Medium sized trees, up to 10 m high; twigs grooved, glabrous. Stipules triangular, glabrous. Leaves: petiole 0.4–0.5 cm long, whitish pale yellow, subquadrangular; blade ovate-oblong, 8.6–15.5 by 3–5.2 cm, coriaceous, base narrowing into petiole and auriculate, apex cuspidate, to 2 cm long, glabrous, pale green above, glaucous beneath; nerves 6–8 pairs, midrib distinct beneath, secondary and tertiary veins inconspicuous. Flowers: bracts triangular, hairy outside. Staminate flowers unknown. Pistillate flowers: sepals ovate, 3–5 by 1–1.8 mm, densely hirsute; petals fan-shaped, densely hairy. Fruits 2–3 per axil, sessile, with persistent calyx and corolla, 0.6–1 cm in diameter, densely hirsute at base.

    T h a i l a n d.— PENINSULAR: Narathiwat.

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

    E c o l o g y.— In evergreen forest, along streams. Altitude: 150–300 m. Fruiting in August.

7. Cleistanthus hirsutulus Hook.f., Fl. Brit. Ind. 5: 280. 1887; Ridl., Fl. Mal. Pen. 3: 192. 1924; Airy Shaw, Kew Bull. 26: 237. 1972; Chin, Limest. Fl. Malaya 1: 229. 1973; Whitmore, Tree Fl. Malaya 2: 79. 1973, H.Keng, Conc. Fl. Singapore: 108. 1990; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 173. 2005.— Cleistanthus  siamensis Craib, Bull. Misc. Inform. Kew 1913: 71. 1913.— Cleistanthus  penangensis Jabl. in Engl., Pflanzenr. IV.147.viii: 21. 1915.— Cleistanthus  cochinchinae Jabl. in Engl., Pflanzenr. IV.147.viii: 21. 1915.— Paracleisthus siamensis (Craib) Gagnep., Bull. Soc. Bot. France 70: 497. 1923.

Shrubs or small to medium-sized trees, up to 8 m high; bark smooth; young branches grooved, short brownish hirsute. Stipules triangular or flagellate, hairy, often bifid. Leaves: petiole 0.2–0.7 cm long, sparsely to densely hirsute; blade obovate-oblong, (2–)4–15 by (0.5–)2–4 cm, chartaceous to subcoriaceous, base obtuse or cuneate to subcordate, apex acute to acuminate, glabrous, sometimes hairy along the midrib on both surfaces or only beneath, densely hairy at base, dark green above, glaucous to pale green beneath; nerves (7)8–13 pairs, conspicuous on both surfaces. Flowers axillary, (1)2–5(6) per fascicle, supported by many bracts, white or whitish green, sessile; bracts triangular or stipule-like, 2.5–3 by 1–2 mm, irregularly lobed, densely hairy outside. Staminate flowers 3–5 mm in diameter; sepals ovate-oblong, 2–2.5 by 1–1.5 mm, glabrous or minutely hairy; petals spathulate or fan-shaped, 0.5–0.7 by 0.5–0.7 mm, margin irregularly lobed, apex deeply 3–5-lobed, clawed, glabrous; disc cup-shaped, margin irregularly crenulate; stamens with triangular androphore, anthers ovate-oblong; pistillode hirsute at base, lobes truncate. Pistillate flowers 5–6 mm in diameter; sepals ovate-oblong, c. 2 by 1 mm, glabrous; petals spathulate or fan-shaped, c. 1 by 1 mm, glabrous, margin irregularly lobed; disc with the outer part funnel-shaped, irregularly lobed, the inner part urceolate enveloping the ovary; ovary nearly globose, 1–2 by 0.8–2 mm, whitish hirsute. Fruits sessile, with 1–2 seeds per locule, densely hairy, slightly hairy at the apex, reddish brown when mature. Seeds obovoid-triangular, reddish brown.

    T h a i l a n d.— NORTHERN: Chiang Mai (Mae Cham), Phrae; NORTH-EASTERN: Nong Khai (Bung Kla), Sakon Nakhon (Phu Phan), Mukdahan, Khon Kaen (Phu Wiang); EASTERN: Nakhon Ratchasima (Pak Thong Chai); SOUTH-WESTERN: Prachuap Khiri Khan (Thap Sakae, Huai Yang, Bang Sapan), CENTRAL: Saraburi (Muak Lek); SOUTH-EASTERN: Sa Kaeo (Aranyaprathet), Chachoengsao (Khao Ang Rue Nai), Chon Buri (Sattahip, Ko Samaesan, Phanat Nikom, Si Racha), Rayong (Ko Samet), Chanthaburi (Pong Nam Ron), Trat; PENINSULAR: Surat Thani (Khao Wong), Nakhon Si Thammarat (Khi Ri Wong), Phatthalung, Songkhla, Narathiwat.

    D i s t r i b u t i o n.— India, Malay Peninsula (type), Singapore, Sumatra, Borneo (Sabah).

    E c o l o g y.— Dry and moist evergreen forest, dry Dipterocarp forest with Pinus, mixed deciduous forest, along streams, in open areas on the beach, over limestone. Altitude: c. 850 m. Flowering in March–July, fruiting in April–December.

    V e r n a c u l a r.— Ko ne (กอนี) (Karen-Chiang Mai); khang khang khae (ขางแข้งแคะ) (Northern); kaeo nam (แก้วน้ำ) (Chanthaburi); mai liang prai (ไม้เลี่ยงไพร) (Bang Sa Phan); ka yi (กะยี) (Prachuap Khiri Khan, Peninsular); ta krim (ตะกริม) (Peninsular).

    U s e s.— Leaves and fruits have stupefying properties.

8. Cleistanthus macrophyllus Hook.f., Fl. Brit. Ind. 5: 278. 1887; Ridl., Fl. Mal. Pen. 3: 192. 1924; Whitmore, Tree Fl. Malaya 2: 81. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 82. 1975; Kew Bull. 32: 73. 1977; Chin, Limest. Fl. Malaya 1: 230. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 174. 2005.

Trees; bark thick, glabrous, lenticellate. Leaves: petiole 0.6–0.8 cm long, glabrous; blade obovate, elliptic-oblong or obovate-oblong, 13–22.5 by 4.8–9 cm, coriaceous, base acute or obtuse, apex mucronate, glabrous on both surfaces; nerves 7–9 pairs, conspicuous on both surfaces. Flowers axillary, supported by many bracts, sessile; bracts ovate, hairy. Staminate flowers: sepals elliptic, glabrous; petals spathulate, clawed, margin irregularly serrate, glabrous; disc cup-shaped, margin entire, stamens with ovate-oblong anthers. Pistillate flowers: sepals ovate-oblong, glabrous; petals subquadrangular, apex 5-lobed, obtuse, glabrous; disc the outer part with crenulate margin, the inner part cylindrical, margin remotely serrate or entire; ovary hirsute. Fruits 3-lobed, 0.7–1.5 cm in diameter, pale brown.

    T h a i l a n d.— PENINSULAR: Trang (Khao Phap Pha).

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

    E c o l o g y.— Evergreen forest, along streams on limestone. Altitude: 150–300 m. Fruiting in March–August.

    V e r n a c u l a r.— Nok non bai yai (นกนอนใบใหญ่).

9. Cleistanthus myrianthus (Hassk.) Kurz, Prelim. Rep. Forest Pegu, App. A: cx. 1875; Forest Fl. Burma 2: 370. 1877; Hook.f., Fl. Brit. Ind. 5: 275. 1887; Ridl., Fl. Mal. Pen. 3: 194. 1924; Gagnep. in Lecomte, Fl.Indo-Chine 5: 482. 1926; Backer & Bakh.f., Fl. Java 1: 474. 1963; Airy Shaw, Kew Bull. 26: 237. 1972; Whitmore, Tree Fl. Malaya 2: 82. 1973; Airy Shaw, Kew Bull. 33: 43. 1978, Kew Bull. Add. Ser. 8: 1. 1980; Kew Bull. 37: 13. 1982; H.Keng, Conc. Fl. Singapore: 108. 1990, P.H.Hô, Câyco Viêtnam 2, 1: 611. 1992; S.Dressler; Blumea 44: 129. 1999; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 174, fig. 38. 2005.— Nanopetalum myrianthus Hassk., Verslagen Meded. Afd. Natuurk. Kon. Akad. Wetensch. 4: 141. 1855.— Kaluhaburunghos myrianthus (Hassk.) Kuntze, Rev. Gen. Pl. 2: 607. 1891, nom. illeg.— Cleistanthus pseudomyrianthus Jabl. in Engl., Pflanzenr. IV. 147.viii: 41. 1915.— Cleistanthus  castus S.Moore, J. Bot. 63, Suppl.: 93. 1925.— Cleistanthus  pseudo-cinereus Airy Shaw, Kew Bull. 33: 43. 1978.— Cleistanthus  myrianthus (Hassk.) Kurz var. concinnus Airy Shaw, Kew Bull. 33: 44. 1978.— Cleistanthus  myrianthus (Hassk.) Kurz var. spicatus Airy Shaw, Kew Bull. 33: 44. 1978.

Medium to large-sized tree, 10–30 m high; evergreen; bark smooth or fissured, reddish-brown; branches glabrous. Stipules c. 1 by 1 mm, caducous. Leaves: petiole (0.4–)0.6–1.0 cm long, hairy; blade elliptic or oblong, 6–13 by (1.5–)2–5 cm, coriaceous, base cuneate, apex acute to acuminate, glabrous above, golden-yellow glossy hairy beneath; nerves 7–10 pairs, conspicuous on both surfaces, tertiary veins obscure. Flowers axillary or in axils of fallen leaves, supported by many bracts, 10–21 per fascicle, staminate flowers numerous, surrounding pistillate flowers; sessile, (0.4–)0.5–0.7 cm in diameter; bracts triangular or stipule-like, 2.5–3 by 1–2 mm, irregularly lobed, densely hairy outside. Staminate flowers: sepals greenish, elliptic, apex acuminate, margin entire or irregularly crenulate, glabrous; petals yellowish green, subchartaceous, fan-shaped or rhomboid or suborbicular, c. 0.7 by 1 mm, margin irregularly lobed, glabrous; disc cup-shaped to obconical; stamens with filaments c. 1.8 by 0.2 mm, anthers cordate-oblong, c. 1 by 0.8 mm. Pistillate flowers pale green; sepals 5( or 6), elliptic, c. 2 by 1 mm; petals spathulate, 1–1.1 by c. 0.5 mm, glabrous, margin irregularly lobed; disc ca. 1 mm in diameter, urceolate, margin irregularly lobed, enveloping the ovary; ovary broad, c. 1 by 2 mm, glabrous. Fruits 1–7 per axil, stipe 5—6 mm long, with persistent calyx and corolla, 3-lobed, 0.9–1.1 cm in diameter, glabrous or slightly golden-yellow hairy at base, reddish purple when mature, remnant of stigmas at the apex. Seeds 1–3, ellipsoid.

    T h a i l a n d.— NORTHERN: Lampang (Mae Salop); SOUTH-EASTERN: Chachoengsao (Khao Ang Rue Nai), Chon Buri, Chantaburi (Khao Soi Dao, Khao Khitchakut), Trat (Ko Chang); PENINSULAR: Surat Thani (Khao Wong), Phangnga (Ao Luek, Khao Luk Lum Ru, Tup Put), Krabi (Phanom Bencha, Ko Lunta), Pattani.

    D i s t r i b u t i o n.— India, Burma, Andaman Islands, Malay Peninsula, Singapore, Indochina, Java (type), Borneo, Philippines, Solomon Islands, Australia (Queensland).

    E c o l o g y.— Dry and moist evergreen forest, on limestone mountains, along streams. Altitude: 50–600 m; Flowering December–April; fruiting February–July. The flowers have a notable smell.

    V e r n a c u l a r.— Thu rian dong (ทุเรียนดง) (Lampang); fai (ไฟ) (Northern).

    U s e s.— Wood for construction, furniture, and for packing. Leaves applied to treat asthma.

10. Cleistanthus papyraceus Airy Shaw, Kew Bull. 21: 368. 1968; Kew Bull. 26: 238. 1972; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 176. 2005.

Shrubs, up to 3 m high; bark smooth and thin, glabrous, lenticellate. Stipules triangular, 1.5–3.5 by c. 1 mm, glabrous. Leaves: petiole 0.3–0.4 cm long, shallowly grooved, glabrous; blade obovate, (2.3–)5–10 by (1–)2–5 cm, chartaceous, base obtuse and subcuneate, apex mucronate, acute or acuminate, glabrous or brownish hairy at base on both surfaces or along both sides of the midrib, dark green above, pale green beneath; midrib distinct above, nerves 7 or 8 pairs, conspicuous beneath, tertiary veins conspicuous beneath. Flowers axillary or on leafless branches, supported by many bracts, 2–8 per fascicle; red or reddish brown, sessile; bracts triangular or stipule-like, c. 1.2 by 1 mm, glabrous outside, tomentose inside. Staminate flowers 2–3 mm in diameter; sepals elliptic-oblong, 2.5–3.5 by c. 0.5 mm, glabrous, with 2–5 veins; petals spathulate or fan-shaped, 0.4–0.5 by 0.3–0.5 mm, margin irregularly lobed or 3-lobed, usually with prickle in the middle, glabrous; disc conical, margin irregular lobes; stamens with triangular androphore, anthers ovate-oblong; pistillode glabrous. Pistillate flowers 3–4 mm in diameter; sepals ovate-oblong, c. 5 by 1 mm, glabrous; petals fan-shaped or oblong, 0.7–0.9 by 0.2–0.7 mm, glabrous, apex almost entire or irregularly lobed; disc cup-shaped, irregularly lobed; ovary nearly globose, c. 1.5 mm in diameer, glabrous. Fruits axillary or on leafless branches, sessile to subsessile, not stipitate, with persistent bracts, calyx and corolla, 3-lobed, 4.5–6 mm in diameter, with 1–2 seeds per locule, glabrous, reddish brown when mature. Seeds subglobose.

    T h a i l a n d.— NORTHERN: Chiang Mai (Hot), Lampang (Chae Hom), Tak (Ban Tak); EASTERN: Nakhon Ratchasima (Pak Thong Chai, Ta Chang, syntype: KERR 9881A, K n.v.); SOUTH-WESTERN: Kanchanaburi (Erawan, Sisawat, syntype: KERR 10160, K n.v.), Prachuap Khiri Khan (Bang Saphan, Huai Yang); CENTRAL: Saraburi (Pra Phut Tha Bat).

    D i s t r i b u t i o n.— Burma.

    E c o l o g y.— Dry evergreen forest, dry dipterocarp forest, along streams and in open areas in forest. Altitude: 50–400 m; Flowering: December–March; fruiting: December–May.

    V e r n a c u l a r.— Khang kang kae (ขางแข้งแคะ), kang kae (แข้งแคะ) (Lampang); tin pae (ตีนแป) (Tak).

11. Cleistanthus polyphyllus F.N.Williams, Bull. Herb. Boiss., sér. 2, 5: 31. 1905; Ridl., Fl. Mal. Pen. 3: 193. 1924; Airy Shaw, Kew Bull. 26: 238. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; Chin, Limest. Fl. Malaya 1: 231. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 177. 2005.

Shrubs or trees, up to 7 m high; bark minutely fissured; young twigs brownish-grey, grooved, densely brownish-yellow hairy, glabrescent, with many apical stipules and/or bracts. Stipules triangular or flagelliform, 6–7 by 0.8–3 mm, densely hairy. Leaves: petiole (0.1–)0.15–0.3 cm long, brownish strigose allover; blade ovate to obovate, 1.5–7 by 0.5–3 cm, chartaceous, base obtuse to cordate, apex acute to acuminate, with straight hairs along the midrib and along the margin above, hairy allover beneath, dark green above, glaucous beneath; venation distinct beneath, midrib also above, nerves 5–9 pairs. Flowers axillary or along branches with small leaves, 3–10 per fascicle, supported by many bracts, whitish-green, sessile; bracts triangular or stipule-like, 4–7 by 0.4–2 mm, hairy outside and along margins. Staminate flowers c. 4 mm in diameter; sepals ovate-oblong, 3–5 by 1–1.8 mm, hairy; petals fan-shaped, c. 0.3 by 0.6 mm, margin irregularly lobed, hairy; disc cup-shaped, margin irregular lobes; stamens with elliptic-ovate anthers, pistillode elliptic-ovate, hairy. Pistillate flowers 5–10 mm in diameter; sepals ovate-oblong, 4–5 by 1.5–2 mm, hairy; petals fan-shaped, 1.2–1.6 by 1–1.5 mm, hairy, margin irregularly crenulate; disc cup-shaped, irregularly lobed, the inner part urceolate enveloping the ovary, with irregularly serrate margin, ovary nearly globose, c. 3 by 1.5 mm, with dense white hairs. Fruits sessile, with persistent calyx and corolla, 3-lobed, 0.6–1 cm in diameter, with 1–2 seeds per locule, densely hairy, with stigma on the top, brown when old. Seeds ellipsoid, brown.

    T h a i l a n d.— PENINSULAR: Chumphon, Surat Thani (Bang Yai, Ko Samui), Phangnga, Krabi (Khao Pu, Hat Nopparattara, Khao Pra Bang Kram), Phatthalung, Trang (Thung Khai), Satun (Kuan Po, Tarutao, Ko Ardung), Songkhla (Hat Yai), Pattani, Yala.

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

    E c o l o g y.— Evergreen forest, dry evergreen forest by streams, open areas on the beach, rubber plantations. Altitude: up to 300 m. Flowering: (January) March–August; fruiting: May–August.

    V e r n a c u l a r.— Mai nok non (ไม้นกนอน) (Chumphon); nok non (นกนอน) (Pattani, Surat Thani, Krabi); yai thip lan (ยายถีบหลาน) (Satun).

    U s e s.— Branches with leaves use for sweeping.

12. Cleistanthus praetermissus Gage, Bull. Misc. Inform. Kew 1914: 240. 1914; Ridl., Fl. Mal. Pen. 3: 193. 1924; Airy Shaw, Kew Bull. 21: 372. 1968; Kew Bull. 26: 238. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 177. 2005.

Shrubs or small trees, up to 8 m high; twigs stramineous, glabrous. Stipules unknown. Leaves: petiole 0.5–0.6 cm long, glabrous, drying black; blade oblong, obovate or elliptic, 8–16.5 by 2.5–5.5 cm, chartaceous, base narrowly cuneate, apex acuminate or caudate, glabrous or rarely strigose along the midrib beneath; nerves 5–9 pairs, distinct beneath. Flowers axillary, only staminate or pistillate ones in spike-like fascicles, supported by many bracts, whitish-green; bracts triangular or ovate, acute to acuminate, hairy outside. Staminate flowers: not seen. Pistillate flowers pedicellate; sepals elliptic, lobes triangular, glabrous; petals sub-spathulate or obovate, shortly clawed, glabrous, margin irregularly crenulate; disc cup-shaped, the inner part urceolate enveloping the ovary, margin irregularly crenate; ovary ellipsoid, densely hairy, stigmas with spathulate lobes. Fruits with 4–5 mm long stipe or not stipitate, with persistent calyx and corolla, 0.8–1 cm in diameter, black, glossy. Seeds 1–2 seeds per locule, brown or mottled.

    T h a i l a n d.— SOUTH-EASTERN: Chanthaburi; PENINSULAR: Phangnga (Takua Pa), Krabi.

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

    E c o l o g y.— Moist and dry evergreen forest, on limestone hills. Altitude: 50–400 m. Flowering: November–December (April); fruiting in May.

    V e r n a c u l a r.— Nok dam (นกดำ).

13. Cleistanthus rufus (Hook.f.) Gehrm., Bot. Jahrb. Syst. 41 Beibl.: 95. 1908, Ridl., Fl. Mal Pen. 3: 195. 1924; Whitmore, Tree Fl. Malaya 2: 82. 1973; Airy Shaw, Kew Bull. 32: 73. 1977; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 178, fig. 39. 2005.— Bridelia rufa Hook.f., Fl. Brit. Ind. 5: 273. 1887.

Shrubs to medium sized trees; bark rough; young twigs rufescent hairy, glabrescent. Stipules triangular, c. 2 by 1 mm, glabrous. Leaves: petiole 0.4–0.6 cm long, grooved, densely hairy; blade oblong or oblong-obovate, 7–18 by 3–6.5 cm, coriaceous, base cuneate to obtuse, apex acuminate, tomentose above when young, glabrous or rufescent hairy along the nerves only when old, tomentose beneath; nerves 8 or 9(–11) pairs, distinct. Flowers axillary or on branches with small leaves or on leafless branches, supported by many bracts, sessile; bracts ovate, 1–1.5 by c. 1 mm, densely hairy. Staminate flowers: sepals obovoid, apex hairy; petals obovate, apex obtuse; disc cup-shaped, irregularly lobed; pistillode hairy. Pistillate flowers: sepals elliptic, c. 1.5 by 1 mm, apex hairy; petals spathulate-oblong, c. 1 by 0.5 mm, glabrous; disc with the outer part cup-shaped, inner part urceolate enveloping the ovary, margin serrate; ovary ovoid, hairy. Fruits axillary or on leafless branches, subsessile, 3-lobed, glabrous, purplish-red when old.

    T h a i l a n d.— PENINSULAR: Ranong (Khlong Naka), Phangnga, Krabi (Khao Pra Bang Khram).

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

    E c o l o g y.— Moist evergreen forest. Altitude: 50–100 m. Fruiting: April–May.

    V e r n a c u l a r.— Nok non bai daeng (นกนอนใบแดง).

14. Cleistanthus sumatranus (Miq.) Müll.Arg. in DC., Prodr. 15(2): 504. 1866; Jabl. in Engl., Pflanzenr. IV.147.viii: 13, fig. 2 A–E. 1915; Ridl., Fl. Mal. Pen. 3: 192. 1924; Backer & Bakh., Fl. Java 1: 474. 1963; Airy Shaw, Kew Bull. 26: 238. 1972; Whitmore, Tree Fl. Malaya 2: 79. 1973; H.Keng, Conc. Fl. Singapore: 108. 1990; S.Dressler, Blumea 44: 139. 1999; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 178. 2005.— Leiopyxis sumatrana Miq., Fl. Ned. Ind., Eerste Bijv: 446. 1861.— Cleistanthus heterophyllus Hook.f., Fl. Brit. Ind. 5: 275. 1887.— Cleistanthus  laevis Hook.f., Fl. Brit. Ind. 5: 277. 1887.— Kaluhaburunghos sumatranus (Miq.) Kuntze, Rev. Gen. Pl. 2: 607. 1891, nom. illeg.— Cleistanthus laevigatus Jabl. in Engl., Pflanzenr. IV. 147, 8: 12. 1915.— Cleistanthus  oligophlebius Merr., Philipp. J. Sci., C. 13: 80. 1918.— Cleistanthus  saichikii Merr., Philipp. J. Sci. 23: 248. 1923.— Paracleisthus subgracilis Gagnep., Bull. Soc. Bot. France 70: 500. 1923.— Cleistanthus euphlebius Merr., Pap. Michigan Acad. Sci. 24: 78. 1939.

Shrubs or trees, up to 20 m high; bark glabrous or minutely fissured, brown or greyish-brown; young twigs grooved, glabrous or minutely hairy near the fruiting areas, old twigs smooth with lenticels. Stipules ovate, caducous, entire to irregularly crenate. Leaves: petiole 0.5(–0.7) cm long, glabrous; blade ovate, 1.5–10 by 0.5–4 cm, sometimes with variable sizes in the same plant, coriaceous, base obtuse, obtuse-cuneate or truncate, apex acuminate with up to 1.5 cm long tip, glabrous, green above, pale green or glaucous beneath; midrib distinct, nerves 4–6(–8) pairs, inconspicuous, tertiary veins inconspicuous. Flowers axillary or along branches with small leaves, supported by many bracts, whitish-green, sessile; bracts ovate, glabrous, usually densely hairy at the base of the glomerule. Staminate flowers 5–6 mm in diameter; sepals ovate-oblong, 3–5 by 1–1.8 mm, apex acute, glabrous, with visible vein; petals fan-shaped or spathulate, c. 0.6 by 0.7 mm, clawed, margin nearly entire; disc cup-shaped, margin thick crenulate; stamens c. 2.5 by 1 mm, anthers ovate; pistillode oblong, 3-lobed at apex, finely warty, glabrous. Pistillate flowers 4–5 mm in diameter; sepals elliptic-ovate, 3–4 by 1–2 mm, apex acute, glabrous; petals spathulate or fan-shaped, c. 0.7 by 0.5 to 0.5 by 0.7 mm, glabrous, margin nearly entire or crenate, with visible vein; disc conical, the outer part thin and with irregular acute lobes, the inner part thin, cylindrical with narrow apex, or urceolate and enveloping the ovary, with crenulate margin; ovary almost globose, c. 2.5 by 1.5 mm, densely hirsute, style thick. Fruits sessile, 3-lobed, c. 1 cm in diameter, with 1–2 seeds per locule or none in some locules, with dense long straight hairs especially along the ridges and in the grooves, with remnant of stigmas, purplish-red when old. Seeds brown, trigonal.

    T h a i l a n d.— NORTHERN: Mae Hong Son, Chiang Mai (Amphoe Muang), Sukhothai (Khirimat); NORTH-EASTERN: Nong Khai (Bung Khla), Sakon Nakhon (Phu Phan), Nakhon Phanom; SOUTH-WESTERN: Kanchanaburi (Erawan), Phetchaburi (Kaeng Krachan), Prachuap Khiri Khan (Pranburi, Sam Roi Yot, Huai Yang); SOUTH-EASTERN: Chachoengsao (Khao Ang Rue Nai), Chon Buri (Bo Thong, Khao Kampang), Trat (Ko Kut); PENINSULAR: Songkhla (Ton-Nga-Chang, Hat Yai), Narathiwat (Khao Tan Yong).

    D i s t r i b u t i o n.— Malay Peninsula, Singapore, Sumatra (type), Java, Borneo, Philippines, Moluccas, Lesser Sunda Islands, Vietnam, China.

    E c o l o g y.— Mixed deciduous forest, dry dipterocarp forest, dry and moist evergreen forest, always by streams. Altitude: up to 775 m. Flowering: January–March; fruiting May–July.

    V e r n a c u l a r.— Fin daeng (ฝิ่นแดง) (Kanchanaburi); ka dong daeng (กะโดงแดง), ngam (งาม) (Prachuap khiri Khan).

15. Cleistanthus tomentosus Hance, J. Bot. 15: 337. 1877; Airy Shaw, Kew Bull. 26: 239. 1972; Roisungnern & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 180, fig. 40, plate IX: 5. 2005.— Cleistanthus  eberneus Gagnep., Bull. Soc. Bot. France 70: 501. 1923.— Cleistanthus  eberneus Gagnep. var. sordidus Gagnep. in Lecomte, Fl. Indo-Chine 5: 502. 1926.

Shrubs or small trees, up to 5 m high; bark smooth, greyish-brown; young twigs grooved, hirsute. Stipules triangular or flagelliform, 3–6 by c. 0.5 mm, densely hairy outside, nearly entire. Leaves: petiole 0.5–0.7 cm long, hairy allover; blade oblong or elliptic-oblong, 5.2–15.5 by 1–5 cm, coriaceous or subcoriaceous, base cuneate to obtuse, apex acute to acuminate, hairy along the veins and margin beneath, dark green above, glaucous or not beneath; midrib distinct above, nerves 7–9 pairs, conspicuous beneath, tertiary veins conspicuous beneath. Flowers axillary or along branches with small leaves or leafless branches, single to numerous per node, supported by numerous bracts, mostly 2 flowers per bract, pale green, yellowish-green or creamy white, pedicellate; bracts ovate, 1.5–2.5 by 0.5–1 mm, acute, densely hairs outside. Staminate flowers 3–5 mm in diameter; sepals elliptic-oblong, 3.5–4.5 by 1.2–1.5 mm, with visible vein, glabrous; petals fan-shaped, 0.4–7 by 0.8–1.1 mm, scattered dots all over, margin irregularly crenate, glabrous; disc conical, margin cushion-shaped, irregularly crenate; stamens with triangular androphore, anthers cordate or ovate-oblong; pistillode oblong-ovate, apex shallowly 3-lobed, warty. Pistillate flowers 4–5 mm in diameter; sepals elliptic, 3–4 by 1–1.5 mm, apex acute, glabrous; petals fan-shaped, 1.2–1.5 by 0.5–1 mm, glabrous, with visible vein, always with acute auricle, margin irregularly crenulate; disc cup-shaped, margin irregularly acutely 5- or 6-lobed; ovary ovoid to almost globose, c. 2 mm in diameter, densely pubescent. Fruits with 4–5 mm long pedicel, 3-lobed, 0.6–1 cm in diameter, with 1–2 seeds per locule with remnant of stigma at the apex, sparsely to densely hairy when young, glabrescent, purplish red. Seeds brown, trigonal.

    T h a i l a n d.— NORTH-EASTERN: Phetchabun; EASTERN: Nakhon Ratchasima; SOUTH-WESTERN: Phetchaburi (Tha Yang); CENTRAL: Saraburi (Amphoe Muang), Nakhon Nayok; SOUTH-EASTERN: Chachoengsao (Khao Ang Rue Nai), Chon Buri (Si Racha, Sattahip), Rayong (Ban Phe), Chanthaburi, Trat (Ko Chang).

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

    E c o l o g y.— Dry evergreen forest, at stream. Altitude: 20–400 m. Flowering: November–April; fruiting: November–June.

    V e r n a c u l a r.— Nuan pang (นวลแป้ง) (Trat, Rayong), mai paeng (ไม้แป้ง) (Trat); nok non (นกนอน) (Nakhon Nayok).