Microcos

Chung, R. C. K. & Soepadmo, E., 2011, Taxonomic revision of the genus Microcos (Malvaceae-Grewioideae) in Peninsular Malaysia and Singapore, Blumea 56 (3), pp. 273-299 : 273-274

MICROCOS

Microcos L. (1753) 514; (1754) 230; Burret (1926) 756; Backer & Bakh.f. (1964) 393; Whitmore & Tantra (1986) 241; Phengklai (1986) 15; (1993) 33; I.M.Turner (1997) 487. — Grewia L. subg. Microcos (L.) J.R.Drumm. (1915) 114. — Grewia L. sect. Microcos (L.) Wight & Arn. (1834) 81; King (1891) 109. — Type species: Microcos paniculata L.

© 2011 Nationaal Herbarium Nederland

Arsis Lour.(1790) 335. — Type species: Arsis rugosa Lour. [= Microcos paniculata L.].

Fallopia Lour.(1790) 335. — Type species: Fallopia nervosa Lour. [= Microcos nervosa (Lour.) S.Y.Hu ].

Omphacarpus Korth. (1842a) t. 42; (1842b) 192. — Grewia L. sect. Omphacarpus (Korth.) Miq.(1859) 204; King (1891) 109. — Type species: Omphacarpus opacus Korth. [= Microcos opaca (Korth.) Burret ].

Inodaphnis Miq. (1861) 357. — Type species: Inodaphnis lanceolata Miq. [= Microcos lanceolata (Miq.) Burret ].

Grewia L. p.p.: King (1891) 108, p.p.; Ridl. (1922) 299, p.p.; Corner (1939) 262, p.p.; Kochummen (1973) 396, p.p.; Corner (1988) 732, p.p.

Evergreen or deciduous shrubs or small to medium-sized trees to 30 m tall; bole usually straight to 60(–70) cm diam, sometimes fluted at base, sometimes with small buttresses. Outer bark smooth to scaly, sometimes lenticellate, green, grey-green or green-brown; inner bark fibrous, red-brown to orange-yellow or even paler and then streaked red; no exudate. Twigs terete. Stipules lobed or unlobed, more or less caducous. Leaves alternate (distichous), petiolate; blade simple, usually entire or sometimes distantly serrate to serrulate, dentate or undulate, 3(–5)-veined at base ( Peninsular Malaysia and Borneo : 3-veined); indumentum of simple, tufted or stellate hairs. Inflorescences terminal and/or axillary, panicles of triflorous cyme-like units (Type A and/or Type B); bracts caducous, rarely persistent; bracts of cyme-like units involucrate, with those of the outer whorl 2 – 3(–4)-lobed and that of the inner whorl narrow and entire. Flowers bisexual, actinomorphic, pedicellate; sepals 5, distinct, free, valvate, margin incurved, apex convexcucullate, covered with tufted or stellate hairs on both sides; petals 5 or fewer due to abortion or absent, caducous, up to half as long as the sepals, clawed-appendage absent, glandular at the base inside, the glands barbellate marginally; androgynophore present, apex expanded into a platform-like structure or not, upper part absent; stamens numerous, rarely 5 –15 (for Moluccas and New Guinea taxa), inserted at the platform-like structure or surrounding the ovary at the apex of androgynophore, filaments distinct, sometimes minutely pilose beneath, anthers dorsifixed, 2-lobed, kidney-shaped, longitudinally de- hiscent; ovary superior, sessile, usually (1–)3(–5)-locular, each locule with (2–)4 –8 ovules; style narrowed towards the apex (subulate), stigma with 3 plano-convex stigmatic arms or inconspicuously lobulate. Fruits drupaceous, usually unlobed or sometimes slightly, shallowly, vertically 3(–4)-lobed near the apex, globose, obovoid or pyriform; mesocarp fibrous; endocarp coriaceous or woody. Pyrenes 1– 3(–4), partly connate or free; fertile pyrene 1–(2 –3) per fruit, each pyrene containing 0–1(– 2) seeds; sterile pyrenes 1–2(–3), conspicuous or inconspicuous. Seeds wingless, with endosperm; cotyledons foliaceous .

Distribution — The genus comprises about 80 species occurring in tropical Africa (not in Madagascar), India, Sri Lanka, Myanmar, Indochina ( Thailand, Laos, Cambodia and Vietnam), southern China (incl. Hainan Island), and throughout Malesia (except the Lesser Sunda Islands). In Malesia, about 52 species are known with two centres of species diversity: 36 species in West Malesia and 16 species in the Moluccas and New Guinea. In Peninsular Malaysia there are 12 species with 2 endemics and Singapore has four species (none endemic).

Habitat & Ecology — In open and shaded places, often along rivers or streams, in primary and secondary lowland to lower montane forests on alluvial to sandy soils; overlying sandstone or acidic rock, but not on limestone, at altitude to 1400 m. Flowering: mainly in March– July; fruiting: May – November.

Uses — The wood of several Microcos species is used locally for general construction under cover (e.g., rafters), and also for making small utensils where strength and elasticity are required, like tool handles, agricultural implements, sporting goods, billiard cues and vehicle bodies. The fibrous bark is utilised for manufacturing ropes and the fruits of most species are reported as edible. The pulped bark is used in Papua New Guinea to stupefy fish ( Boer & Sosef 1998).