Alangium ridleyi King

Dewilde, W. J. J. O. & Duyfjes, B. E. E., 2017, Taxonomy of Alangium section Conostigma (Alangiaceae), Blumea 62 (1), pp. 29-46 : 45

18. Alangium ridleyi King — Fig. 7

Alangium ridleyi King (1902) 78; Wangerin (1910) 12; Ridl. (1922) 893; Bloemb. (1935) 278, f. 5a‒i; (1939) 215, f. 10a‒i; Wijedasa et al. (2014) 233,f. 1–3. — Lectotype (designated by Wijedasa et al.2014): Ridley 4941 (SING SING0059170; iso BM BM000944962,CAL n.v., K K000077044, US US 00127566), Singapore, Botanic Garden Jungle, 1893, fl.

Marlea costata auct. non Boerl.: Valeton (1906) 267, t. 179. — Alangium costatum (Valeton) Wangerin (1910) 12, f. 3a‒e, nom. illeg. — Voucher specimen: Unknown collector, Hort. Bog. VIII H 17 (BO, K K000704829, L L.2497595), Sumatra, Bangka.

Tree to 40 m tall; twigs brown, (4–) 5–10 mm diam, at apex and leaf bud with dense minute scale-like hairs c. 0.1 mm long, glabrescent. Leaves: petiole 1.5–2(–3) cm long, lamina glabrous, drying greenish brown, elliptic or elliptic-obovate, 15–25(–40) by 10–12(–20) cm, base symmetric, (rounded or) short cuneate, apex short acuminate; veins pinnate, 8–14(–18) per side, loop-veined especially towards apex of lamina; tertiary venation reticulate or faintly fine-scalariform. Inflorescences glabrous or with scale-like hairs 0.1 mm long or less, with 3–10 flowers, simple or 2–3-branched, sessile or to 5(–10) mm peduncled. Flowers minutely hairy; pedicel 1–4 mm long; corolla in bud (12–) 15–18 mm long, not thickened at base, apex blunt (or acute), ovary and calyx c. 5 mm long, faintly 10–12-ribbed, limb not or only somewhat spreading, 2(–3) mm long, at margin 4–5 mm wide, (sub)truncate; petals 5 or 6, finely hairy, ± carnose, c. 15 mm long (minutely hairy or) glabrous inside; stamens 5 or 6, filament c. 5 mm long, broad but not thickened at base, hairy at apex, anther 10–12 mm long, connective glabrous; style glabrous (Borneo) or hairy, cylindrical or obconical, c. 10 mm long, stigma conical. Fruit 1 or 2 per infructescence, ripening purple or black, minutely hairy, glabrescent, ellipsoid, (25–) 30–40 mm long, coarsely 10–12(–14)-ribbed, calyx remnant broad, subtruncate, 5–7 mm wide.

Distribution — S Peninsular Thailand; in Malesia: Sumatra (Simeuleu Isl., Bangka, S Sumatra, Riau), Peninsular Malaysia (Kedah, Perak, Trengganu, Pahang, Selangor, Negeri Sembi- lan, Johor), Singapore, Borneo (E Kalimantan; doubtful in C Kalimantan & Sabah).

Habitat & Ecology — Primary forest, mixed dipterocarp forest, hillside, undulating country, flatland, rocky valley, rocky ridge crest, rocky riverbank; granite; from sea-level to 550 m altitude; flowering February to October; fruiting January, May, July, October to November.

Field-notes — Whitmore 8929: “fruit green, slightly ribbed, turning pinkish magenta, with a sour translucent juicy aril”. Stilt-roots and buttresses sometimes present; bark smooth; flowers fragrant.

Vernacular names ― Taramajang pajo, Medang mata oedang, Rengengit fatoeh, Medang sengeh, Melepangan paja (Sumatra); Mentulang (Malay).

Note — Material from Borneo, at present treated under Alangium ridleyi , could be erroneously regarded as belonging to A. oblongum . As noted under A. oblongum , the distinction between the two species is not easy and sometimes not clear. In A. ridleyi , however, the filaments are broader, and hairy at the apex, in A. oblongum the filaments are comparatively nar- rower, and hairy almost all over.