Malesian Euphorbiaceae Descriptions

73. MICRODESMIS (Pandaceae)

 

P.C. van Welzen

 

Van Welzen, P.C. 2011. Pandaceae (formerly Euphorbiaceae s.l. subfam. Acalyphoideae tribe Galearieae). In: Nooteboom, H.N. (ed.), Flora Malesiana ser. 1, 20: 15–43.

 

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Genus description

Subgenus description

Key to the species

Species descriptions

 

Microdesmis Hook.f. ex Planch.

 

    Microdesmis Hook.f. ex Planch., Hooker’s Icon. Pl. 8 (1848) t. 758; Baill. Ιtude Euphorb. (1858) 668; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1041; Benth. in Benth. & Hook.f., Gen. Pl. 3 (1880) 287; Hook.f., Fl. Brit. India 5 (1887) 380; Pax in Engl., Nat. Pflanzenfam. III, 5 (1890) 82; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iii (1911) 105; Ridl., Fl. Malay Penins. 3 (1924) 258; Gagnep. in Lecomte, Fl. Indo-Chine 5 (1926) 458; Pax & K.Hoffm. in Engl. & Harms, Nat. Pflanzenfam. ed. 2, 19c (1931) 172; Robyns, Fl. Parc Nat. Alb. 1 (1948) 472; Keay, Fl. W. Trop. Afr., ed. 2, 1 (1958) 392; J.Lιonard, Bull. Jard. Bot. Ιtat. Bruxelles 31 (1961) 159; Fl. Congo Rwanda-Burundi 8(1) (1962) 102; J.-G.Adam, Mιm. Mus. Natl. Hist. Nat., B, Bot. 20 (1971) 499; Airy Shaw, Kew Bull. 26 (1972) 362; Whitmore, Tree Fl. Malaya 2 (1973) 118; Berhaut, Fl. Ill. Sιnιgal 3 (1975) 539; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 222; Kew Bull. 36 (1981) 367; Radcl.-Sm., Fl. Trop. E. Afr. Euph. 2 (1988) 581; G.L.Webster, Ann. Missouri Bot. Gard. 81 (1994) 68; Radcl.-Sm., Gen. Euphorbiacearum (2001) 126; Pooma in Welzen & Chayam., Fl. Thailand 8, 2 (2007) 450; Welzen in Noot., Fl. Males. ser. 1, 20 (2011) 38; Kubitzki in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 271, Fig. 61a. —  Type: Microdesmis puberula Hook.f. ex Planch.

    Tetragyne Miq., Fl. Ned. Ind., Eerste Bijv. (1860) 463; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1254. —  Type: Tetragyne acuminata Miq. (= Microdesmis caseariifolia Planch.).

    Worcesterianthus Merr. (Olacaceae), Philipp. J. Sci. 9, Bot. 9 (1914) 288; Sleumer in Engl. & Harms, Nat. Pflanzenfam. ser. 2, 16b (1935) 22. —  Type: Worcesterianthus casearioides Merr. (= Microdesmis caseariifolia Planch.).

 

Shrubs to trees, dioecious. Indumentum simple, whitish hairs, most parts glabrescent. Stipules triangular, persistent, outside hairy, inside glabrous. Leaves alternate, distichous, simple; petiole short, slender, not pulvinate, usually channelled above; blade with asymmetric base, margin laxly serrate to serrulate to seemingly entire in older leaves, tiny glands at apex of teeth or in very small crenations in entire leaves, venation pinnate, with few nerves, latter looping and closing far from margin, veinlets reticulate. Inflorescences axillary fascicles to on a short peduncle after several flowering periods, with a single to many flowers, pistillate fascicles usually with fewer flowers than staminate ones; bracts minute, triangular, sericeous outside, glabrous inside. Flowers shortly pedicelled, calyx 5-lobed, hairy on both sides, hairs papilla-like, lobes imbricate; petals 5, c. twice as long as sepals, hairy with papilla-like hairs in especially upper half on both sides, valvate or imbricate in bud; disc absent. Staminate flowers: stamens 5 (Africa), oppositisepalous, or 10 (Asia) stamens, outer whorl with longer filaments, oppositisepalous, inner whorl with shorter filaments, oppositipetalous, anthers basifixed, thecae 2, parallel, opening with introrse or latrorse longitudinal slits, connective slender, apex blunt or with long extension; pistillode columnar (Asia) or pentagonal in lower part and cylindrical in upper part (Africa). Pistillate flowers: ovary cylindrical with flat top, (1)2–5-locular, glabrous to slightly hairy, 1 ovule per locule, styles absent, stigmas completely split, with long, pectinate papillae. Fruits ovoid to flattened ovoid drupes, glabrous, wall often knobbly because of thickened parts in ectocarp and/or endocarp, mesocarp fleshy, endocarp thick, wall knobbly, basally with thickened triangular part, central column slender. Seeds compressed ovoid, without fleshy appendages.

    Distribution —  A palaeotropical genus of 10 species, 8 in Africa (subgenus Microdesmis), 2 in Asia (subgenus Ganitrocarpus).

    Note —  The genus is divided into two subgenera, subgenus Microdesmis has 5 stamens and non-apiculate connectives; subgenus Ganitrocarpus has 10 stamens. The second character for this subgenus, the apiculate connective, is redundant, because M. magallanensis lacks this extension of the connective.

 

Subgenus Ganitrocarpus

 

    Microdesmis Subgenus Ganitrocarpus Planch., Hooker’s Icon. Pl. 8 (1858) t. 758; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1041; Pax in Engl., Nat. Pflanzenfam. III, 5 (1890) 82; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iii (1911) 105; in Engl. & Harms, Nat. Pflanzenfam. ed. 2, 19c (1931) 172; Welzen in Noot., Fl. Males. ser. 1, 20 (2011) 39. — Type species: Microdesmis caseariifolia Planch.

 

Stamens 10.

    Distribution —  Two species in SE Asia of which one endemic in the Philippines (Luzon), the other ranging from SE Asia main land to the Philippines (Palawan)

 

Key to the species

 

1a.

Leaf blade length/width ratio 2.1–4.5, margin retrorse, indistinctly to distinctly serrulate, older ones entire. Connective of stamens long apiculate appendix; pistillode 0.8–1.3 by 0.5–0.6 mm. Ovary glabrous. Fruits ovoid, 5–6.5 by 5–6.5 mm, warty. SE Asia main land to the Philippines (Palawan)

1. Microdesmis caseariifolia

1b.

Leaf blade length/width ratio 1.4–2.9, margin entire (only very young, immature leaves laxly serrulate). Connective of stamens without appendix; pistillode c. 3 by 1 mm. Ovary basally hairy. Fruits flattened ovoid, 11–18 by 11–16 by 7–10 mm, smooth. Philippines (Luzon, Sibuyan)

2. Microdesmis magallanensis

 

1. Microdesmis caseariifolia Planch.

 

    Microdesmis caseariifolia Planch., Hooker’s Icon. Pl. 8 (1848) t. 758 (’caseariaefolia’); Clos, Ann. Sci. Nat., Bot. sιr. 4, 4 (1855) 382; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1041; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1041; Hook.f., Fl. Brit. India 5 (1887) 380; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iii (1911) 106; Merr., Enum. Philipp. Fl. Pl. 2 (1923) 451; Ridl., Fl. Malay Penins. 3 (1924) 258; Gagnep. in Lecomte, Fl. Indo-Chine 5 (1926) 460, Fig. 56: 7—13; M.R.Hend., J. Malayan Branch Roy. Asiat. Soc. 17 (1939) 71; Airy Shaw, Kew Bull. 26 (1972) 362; Whitmore, Tree Fl. Malaya 2 (1973) 118; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 222; Kew Bull. 36 (1981) 367; Pooma in Welzen & Chayam., Fl. Thailand 8, 2 (2007) 450, Fig. 45; Welzen in Noot., Fl. Males. ser. 1, 20 (2011) 39, fig. 8a–g; map 5. — Lectotype (designated by Welzen, 2011): Lobb 337 (K), (Burma/Myanmar), Moulmein (paratype: Griffith s.n. (K), Malacca).

    Tetragyne acuminata Miq., Fl. Ned. Ind., Eerste Bijv. (1861) 463; Mόll.Arg. in DC., Prodr. 15, 2 (1866) 1254; Hallier, Meded. Rijks-Herb. 1 (‘1910’, 1911) 11. — Type: Teijsmann HB 4362 (holo U), Sumatra, Lampongs, Mangala.

    Microdesmis philippinensis Elmer, Leafl. Philipp. Bot. 4 (1911) 1300. — Syntypes: Elmer 12620 (K, L), Philippines, Brooks Point (Addison Peak); Elmer 13151 (K, L), Philippines, Palawan, Puerto Princesa (Mt. Pulgar).

 

           

 

Shrub to understorey tree, up to 15(–30) m high, d.b.h. up to 25 cm, widely branched above the middle; branches laxly and numerously rebranched, green, flowering branches 1.3–1.8 mm thick; youngest part hairy, glabrescent. Outer bark grey (with light patches) to light yellow to greenish to reddish brown to dark brown to blackish, smooth, c. 0.2 mm thick; inner bark khaki- green to white to yellowish to reddish, c. 1.7 mm thick; sapwood white to white yellow to yellowish to pale orange to pale brownish, medium hard, odourless, tasteless. Stipules 1–3 by 0.3–0.6 mm. Leaves: petiole 3–11 mm long, pilose to (sub)glabrous, glabrescent, green; blades (ovate to) elliptic (to obovate), 14–18.5 by 3.5–9.7 cm, length/width ratio 2.1–4.5, pergamentaceous to coriaceous, base obtuse to attenuate, margin recurved, indistinctly to distinctly serrulate, older ones entire, apex acuminat to caudate, tip mucronulate, upper surface glabrous except usually for the hairy basal part of the midrib, glossy dark green, usually drying bluish green, rather shiny, lower surface (sub)glabrous to hairy, lighter green, drying dull light green(-brown), venation not to slightly raised above, raised beneath, nerves 5–8 pairs. Flowers white to greenish yellow to yellow to orange, fragrant. Staminate flowers 2.8–5.5 mm in diameter; pedicel 1.7–3 mm long, pilose to (sub)glabrous; calyx 0.8–1.3 mm high, lobes basally united, ovate, 0.7–0.8 by 0.6–0.8 mm; petals elliptic to obovate, 1.6–2.8 by 0.8–1.4 mm, apex rounded, often somewhat incurved; stamens 10, outer filaments c. 0.7–0.8 mm long, inner ones 0.5–0.6 mm longs, anthers c. 0.4 by 0.3 mm, connective with long apiculate extension, often not yet (fully) developed in bud; pistillode warty, 0.8–1.3 by 0.5–0.6 mm, glabrous. Pistillate flowers 3.3–9 mm in diameter; pedicel 2–2.7 mm long, hairy; calyx 1.3–2 mm high, lobes ovate, 0.8–1.2 by 0.9–1.2 mm, thick; petals elliptic to obovate, 2.5–4.8 by 1.2–2.8 mm, like those of staminate flowers; ovary 1.3–1.8 by 0.9–1.3 mm, 2-locular, glabrous, one ovule per locule; stigmas 0.9–1.3 mm long. Fruits pendant, ovoid, 5–6.5 by 5–6.5 mm, warty, light green turning to deep orange to red; endocarp dark brown. Seeds c. 3.2 by 2 mm, black, crustaceous.

    Distribution — Burma to S. China, Hainan, Malesia: Malay Peninsula, Sumatra, Borneo, Philippines (Palawan, Bancalan, Balabac; Merrill, 1923).

 

dots = Microdesmis caseariifolia Planch.; stars = M. magallanensis (Elmer) Steenis

 

    Habitat & Ecology — On level to hilly terrain in primary lowland (dipterocarp) rainforest to mixed deciduous forest, riverine forest, secondary forest, logged areas, in thickets. Soil: Clay-loam, loam, sandy loam, sand, sandstone, limestone, granite, ultrabasic alluvial deposits, ultramafic chromite. Altitude: 10–800 m. Flowering and fruiting whole year through.

    Vernacular names — Vietnam: Chanh σc, Dok ko bang, A luan te he (Gagnepain, 1926). Malay Peninsula: Chateng, Chareh rambeh; Chemberai burong (Temiar); Chempilai burong; Cheprai gila (Temuan); Kenidai badak, Sigoniah (partly after Ridley, 1924). Sumatra: Kaju minak-minak (or Kaju miak-miak), Kaju tulang. Borneo: Kalimantan: Baranakan; Pirpingdamik; Sabah: Baleyusa andu (Dusun); Kolakos (Kadazan Tuaran); Luluning, Magapa-apa (Murut); Pasiau (Kwijau). Philippines: Balanatu, Bunga-bunga, Manlato (Tagbanua); Banato (partly after Elmer, 1911 and Merrill, 1923).

    Uses — Fresh plant juice is used agains caries. Sometimes utilised for house construction (posts).

    Note — Elmer (1911) recognized M. philippinensis, because it differs from M. caseariifolia in ‘petals not being orbicular nor pubescent on both sides; stamens in ours 10, their blunt anthers not long apiculate or caudate; and fruits when ripe yellow not red’. The Palawan specimens (formerly M. philippinensis) do not differ from the other M. caseariifolia specimens. The petals are never orbicular, vary between glabrescent and hairy, the stamens are always 10 and the long extension is absent when the bud is still young. Ripe fruits colour from yellow to red, thus probably Elmer did not see mature fruits yet.

 

2. Microdesmis magallanensis (Elmer) Steenis

 

    Microdesmis magallanensis (Elmer) Steenis, Acta Bot. Neerl. 4 (1955) 480; Welzen in Noot., Fl. Males. ser. 1, 20 (2011) 41, Fig. 8h, i; map 5. — Flacourtia magallanensis Elmer (Flacourtiaceae), Leafl. Philipp. Bot. 4 (1912) 1519. — Worcesterianthus magallanensis (Elmer) Merr. (Olacaceae), Philipp. J. Sc. 10, Bot. (1915) 270; Enum. Philipp. Fl. Pl. 2 (1923) 117; Sleumer in Engl. & Harms, Nat. Pflanzenfam. ser. 2, 16b (1935) 22. — Type: Elmer 12476 (iso K, L), Philippines, Sibuyan Island, Capiz Prov., Magallanes (Mt. Giting-giting).

    Worcesterianthus casearioides Merr. (Olacaceae), Philipp. J. Sci. 9, Bot. (1914) 288. — Type: M. Ramos BS 14943 (?), Philippines, Luzon, Laguna Prov., between San Antonio and Paete (Paratype: M. Ramos BS 16541 (L, 2 sheets), Philippines, Luzon, Province of Laguna, San Antonio).

 

   

 

Shrubby or tree-like, up to 15 m high, d.b.h. up to 30 cm; flowering branches 1.5–2 mm thick; youngest part hairy, glabrescent. Outer bark light brown; inner bark dark brown; wood yellowish. Stipules 0.5–1 by 0.5–0.6 mm. Leaves: petiole 6–9 mm long, pilose to (sub)glabrous, glabrescent; blades elliptic, 4.4–25 by 1.5–8.6 cm, length/width ratio 2.1–4.5, pergamentaceous to coriaceous, base attenuate to widely cuneate, margin flat, entire with minute crenations in which minute glands, very young, immature leaves laxly serrulate with glands at teeth apices, apex acuminate (to caudate), tip not mucronulate, upper surface glabrous except usually for the hairy basal part of the midrib, usually drying shiny greenish to brownish, lower surface (sub)glabrous to somewhat hairy on venation, drying dull light greenish to brownish, venation not to slightly raised above, raised beneath, nerves 6–8 pairs. Flowers white. Staminate flowers c. 3 mm in diameter; pedicel c. 0.5 mm long, pilose; calyx 1.3–1.8 mm high, connate for more than halfway, lobes triangular, c. 0.5 by 1 mm; petals ovate to elliptic, 2.4–3 by c. 1 mm, apex rounded to acute, incurved; stamens 10, outer filaments 1.8–2.3 mm long, inner ones c. 1.5 mm longs, anthers c. 0.4 by 0.4 mm, connective without extension; pistillode warty, c. 3 by 1 mm, hairy. Pistillate flowers not seen, according to Merrill (1914): pedicel c. 2 mm long; calyx like staminate flowers; petals elliptic, c. 4 by 1.6 mm; ovary 2-locular, basally hairy; stigmas c. 2 mm long. Fruits flattened ovoid, 11–18 by 11–16 by 7–10 mm, glabrous, smooth. Seeds not seen.

    Distribution — Malesia: Endemic in the Philippines (Luzon, Sibuyan).

 

stars = M. magallanensis (Elmer) Steenis; dots = Microdesmis caseariifolia Planch.

 

   Habitat and Ecology — Dipterocarp forest. Altitude: c. 200 m. Flowering: April; fruiting: February, April, May, September to October.