Alangium denudatum (Bloemb.) W.J.de Wilde & Duyfjes, 2017

Dewilde, W. J. J. O. & Duyfjes, B. E. E., 2017, Taxonomy of Alangium section Conostigma (Alangiaceae), Blumea 62 (1), pp. 29-46 : 32

3. Alangium denudatum (Bloemb.) W.J.de Wilde & Duyfjes , stat. nov. — Fig. 1

Alangium denudatum (Bloemb.) W.J.de Wilde & Duyfjes. — Alangium nobile (C.B.Clarke) Harms var. denudatum Bloemb. (1935) 276; (1939) 212, f. 9f. — Type: Beguin 582 (holo BO; iso L L.1162840, SING, U 2 sheets U.1230478, U.1230480), Sumatra, Bengkalis , 6 m alt., 15 Jan. 1920, fl .

Tree 20–33 m tall; twigs dark brown, 2–3(–4) mm diam, densely minutely rusty hairy (hairs 0.1–0.2 mm long), late glabrescent; leaf bud minutely hairy (hairs c. 0.1 mm long). Leaves: petiole 0.5–1.2 cm long; lamina drying brown, glabrous, except minute hairs on midrib and veins below, ovate-elliptic or elliptic(-oblong), 7–18 by 4–6(–7) cm, base symmetric, (broadly rounded or) narrowly cordate, apex (blunt or) acute or acute-acuminate; veins seemingly completely pinnate but faintly 3–5-plinerved at base, 8–12 at each side, usually loop-veined; tertiary venation thin, finely (reticulate-)scalariform. Inflorescences densely minutely hairy, of 1 or 2 (or 3) flowers, axillary to a leaf, sessile (rarely 1 or 2 flower(s) on a peduncle to 5 mm long). Flowers minutely hairy (as twigs); pedicel 8–10 mm long; corolla in bud 18–20 mm long, base swollen, apex blunt; ovary and calyx 5–6 mm long, finely ribbed; limb c. 2 mm long, at margin 5–6 mm wide, lobes 5 (or 6), conspicuous, triangular; petals 5 (or 6), inside densely long rusty hairy (hairs c. 0.4 mm long), 18–20 mm long; stamens 5, filament c. 2 mm long, the lower half not much thickened, densely (setose) hairy, the upper portion slender, glabrous, anther c. 10 mm long, connective glabrous; style densely hairy, c. 18 mm long, stigma conical. Fruit 1 (or 2?) per infructescence, ripening colour not recorded, densely rusty hairy (hairs 0.2–0.3 mm long), (ovoid-) ellipsoid, 27–30 by 16–20 mm, 10-ribbed; calyx remnant as calyx in flower.

Distribution — E Sumatra (Bengkalis), Singapore (Mandai Road), Borneo (Kalimantan, Sampit; not recorded from Brunei, Sarawak, and Sabah).

Habitat & Ecology — Marsh forest (mixed peat swamp forest), at sea level; flowering in January and July; fruiting in April and July.

Field-notes — Stilt-roots 2 m high, spreading 1.2 m; flowers fragrant.

Vernacular name — Mara lepang.

Additional specimens studied. SUMATRA, Buwalda 295 (= bb 28518), Riouw en Ond. Indragirische bovenlanden, Belimbing, 6 m alt., 2 July 1939, st. – SINGAPORE, Kiah SFN 37708, Mandai Road, low alt., 26 July 1940, fl., fr. – KALIMANTAN, Kostermans 4659, Sampit region, 5 m alt., Apr. 1948, fr.

Note ― The somewhat deviating Beccari specimens from Sarawak ( Beccari 2477, 2927, and 3611 (all K) discussed by Bloembergen (1939) under A. nobile , are not included in A. denudatum ).