Microcos laurifolia (Hook.f. ex Mast.) Burret

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 : 291-293

9. Microcos laurifolia (Hook.f. ex Mast.) Burret — Fig. 11 ; Map 8

Microcos laurifolia (Hook.f. ex Mast.) Burret (1926) 771; Phengklai (1986) 56, f. 25; (1993) 39, f. 25; I.M.Turner (1997) 487; R.C.K. Chung et al. (2005b) 113. — Grewia laurifolia Hook.f. ex Mast. (1874) 392; King (1891) 114; Baker f. (1924) 13; Kochummen (1973) 399; (1997) 429; Corner (1988) 733. — Lectotype ( Chung et al. 2005b): Maingay 1647 (holo K (with flower buds); iso K (with fruits)), Peninsular Malaysia, Malacca.

Grewia florida auct.non Miq. 1861: Ridl.(1922) 303,p.p. (excl. syn. G. laurifolia ).

Medium-sized tree to 25(– 45) m tall, dbh to 60(–70) cm; buttresses short or absent; bole fluted at base. Outer bark smooth or finely fissured, sparsely lenticellate, greyish brown; inner bark brown with purplish streaks, granular; sapwood pale yellow to white. Twigs smooth, greyish brown to black, sparsely covered with simple or minute stellate hairs when young, greyish brown to brown, slightly grooved and glabrous when older. Stipules early caducous. Leaves olive-green to reddish brown or dark brown on both sides, subcoriaceous, glabrous or sparsely covered with simple or minute stellate hairs on midrib and secondary veins on both sides; petioles (10 –)14– 26(– 29) mm long, 1–1.5(–2) mm thick, dark brown to black, apically swollen for 5 –10 mm long, densely covered with simple or minute stellate hairs near the distal end above, sparsely covered with simple or minute stellate hairs towards the proximal end beneath; blade elliptic, narrowly oblong or lanceolate, equilateral, (7–)9–17(–18.5) by (3 –)3.5–6.5(–7) cm, base shortly attenuate or rounded, margin entire, not ciliate, apex acute or acuminate, acumen 0.5 –1.5 cm long with a pointed tip; midrib and secondary veins impressed or rarely flattened above, raised beneath; secondary veins 3 –4 pairs, basal pair reaching almost 0.75 of blade length, forming an angle of less than 45° with the midrib; glabrous pocket-type domatia sometimes present beneath in axils of basal vein pair; tertiary veins reticulate, obscure above, conspicuous or obscure beneath. Inflorescences Type A and sometimes Type B panicles, terminal or axillary, (3–) 4– 9 cm long, densely covered with minute stellate hairs; bracts early caducous; involucral bracts of outer whorl 3 – 3.5 mm long, (2 –)3-parted, lobes lanceolate, (1–) 1.5 – 2 mm long, apex acute, smooth outside, densely covered with stellate hairs on both sides, that of inner whorl oblanceolate or rarely narrowly elliptic, 2.5–4 by 0.7–1.3 mm, apex obtuse or obliquely truncate, densely covered with stellate hairs on both sides. Flower buds obovoid, (2.5 –)3 – 3.5(– 4) by 1.5– 2 mm, densely covered with stellate hairs; pedicels (0.4 –)0.8 –1(–1.2) mm long, 0.5 – 0.8 mm thick, densely covered with stellate hairs; sepals narrowly oblong or oblanceolate, 4 – 5.5 by 0.8 –1.5 mm, densely covered with stellate hairs outside, sparsely covered with stellate hairs towards the apex inside; petals 5 or fewer by abortion, oblong, 2.2 – 2.8 by 0.8 –1 mm, apex shallowly 2 – 3-lobed, outside densely covered with stellate hairs at base to c. 0.5 of its length and sparsely covered with glandular trichomes towards the apex, inside densely covered with stellate hairs around glands to c. 0.5 of its length and sparsely covered with glandular trichomes towards the apex; glands broadly obovoid; androgynophore obovate in outline, 1–1.2 mm long, 0.5 –0.8 mm diam, shallowly longitudinally grooved, glabrous, apical part expanded into a platform-like structure of c. 0.2 mm wide with undulate rim covered with stellate hairs; stamens with filaments 2–2.5 mm long, glabrous, anthers c. 0.2 mm diam; ovary 3-locular, globose or obloid, 0.6 – 0.7 mm diam, oblate or transversely elliptic in cross section, sparsely covered with glandular trichomes in buds and lesser in flowers; style 2 –2.5 mm long, glabrous. Infructescences densely covered with minute stellate hairs. Fruits ripening yellow, pyriform, with 2 –3 shallow vertical furrows, 1.5– 2 by 0.8 –1.3 cm, drying brown to dark brown, glabrous; apex rounded, pseudostalk narrowed, 5 –8 mm long; exocarp membranous; mesocarp 1–1.5 mm thick; endocarp 0.5 –1 mm thick, woody. Pyrenes 3, free; fertile pyrenes 1–2, 1-seeded, 4 – 6 mm long; sterile pyrenes 1–2, conspicuous; pyrenes arranged triangularly, with the fertile one larger than the sterile pyrenes.

Distribution — Peninsular Thailand, Sumatra, Peninsular Malaysia and Borneo ( Brunei).

Habitat & Ecology — In mixed dipterocarp forest; on hillsides, ridges, or near streams, to 1000 m altitude. Flowering: January, March– June, November –December; fruiting: January, April– June.

Vernacular names — Damak-damak air, jejawai (Malay).

Figures

Map 8 Distribution of Microcos laurifolia (Hook.f. ex Mast.) Burret in Peninsular Malaysia.

Fig. 11 Microcos laurifolia (Hook.f.ex Mast.) Burret.a. Flowering leafy twig;b. detail of abaxial leaf surface near midrib;c. flower buds surrounded by involucral bracts; d. longitudinal section of flower bud; e. flower with sepals and petals removed; f. abaxial surface of petal; g. adaxial surface of petal with gland at base; h. stigma; i. fruiting leafy twig; j. longitudinal section of fruit (a –h: Kochummen FRI 16338; i, j: Ando et al. AKK 416). — Drawn by R. Wise, FHO.