Alangium circulare B.C.Stone & Kochummen

Dewilde, W. J. J. O. & Duyfjes, B. E. E., 2017, Taxonomy of Alangium section Conostigma (Alangiaceae), Blumea 62 (1), pp. 29-46 : 30-32

2. Alangium circulare B.C.Stone & Kochummen

Alangium circulare B.C. Stone & Kochummen (1975) 219, f. 1‒2; Berhaman (1995) 7. — Type: Saleh ak Nantah S 24325 (holo SAR n.v.; iso A n.v., BO, K K001096812,KEP n.v., L L0009818,SAN n.v., SING),Borneo, Sarawak, Kuching, Bukit Siol, 29 Oct. 1964, fl.

Tree c. 9 m tall; twigs dark brown, c. 3 mm diam, towards apex with minute hairs, glabrescent; leaf bud minutely hairy. Leaves: petiole 0.5–1.5 cm long; lamina drying greenish, glabrous, subcircular or broadly obovate, 4.5–9.5 by 3.5–8.2 cm, base symmetric, short-cuneate, apex broadly rounded and somewhat emarginate; veins pinnate (at base plinerved), 4 or 5 on each side, loop-veined near margin; tertiary venation coarsely reticulate-scalariform. Inflorescences sparsely fine-hairy, of 1 (or 2) main branches (peduncles) from the leaf axil, each 1–2-flowered; peduncle (s) c. 10 mm long. Flowers finely minutely hairy (hairs c. 0.1 mm long); pedicel 2–3 mm long; corolla in bud c. 20 mm long, base slightly swollen, apex (sub)obtuse; ovary and calyx 5(–6) mm long, ribbed; limb spreading, c. 1.5 mm long, at margin c. 7 mm wide, truncate or hardly lobed; petals 5, inside somewhat short-hairy, 22–25 mm long; stamens 5, filament 10–11 mm long, thickened and hairy towards base, anther 10–12 mm long, connective glabrous; style densely hairy (hairs c. 0.5 mm long), c. 20 mm long, stigma small, conical. Fruit not known.

Distribution — Borneo ( Sarawak), only known from the type.

Habitat & Ecology — Disturbed primary heath forest; white podsolised soil; flowering in October.

Proposed IUCN (2012) conservation assessment — Criti- cally Endangered ( CR), since the type locality no longer exists and the species is only known from the type collection .

Notes — 1. We checked the hairiness of the locule inside as mentioned by Stone & Kochummen (1975); with a magnification of × 60 we could detect some minute hairs.

2. The Sarawak botanist Julia Sang informed us that Bukit Siol (now within Kuching town) is converted into human set- tlement and that in 1964 when A. circulare was collected the forest type was heath forest on podsolised white soil .