Dimorphocalyx pauciflorus (Merr.) Airy Shaw

7. Dimorphocalyx pauciflorus (Merr.) Airy Shaw View in CoL — Fig. 1a, h View Fig ; Map 1

Dimorphocalyx pauciflorus (Merr.) Airy Shaw (1967) View in CoL 413. — Ostodes pauciflorus Merr. (1916a) 72; (1921) 345. — Type: Hose 244 (iso A, K, L, P), Malaysia, Sarawak, Baram District , Baram .

Shrubs to treelets, to 8 m high, dbh to 8 cm; young twigs greenish grey; flowering braches 1.5–2 mm thick, round, yellowish brown when dry, smooth. Indumentum of yellowish hairs most parts mainly glabrous. Outer bark grey to grey-brown, smooth. Stipules triangular, 1.8–3 by 1.8–2.5 mm, margin with few hairs, thick but margins thinner. Leaves: petiole 2.5–7 mm long, 0.8–1.7 mm diam, deeply grooved above, completely pulvinate, glabrous; blade slightly ovate to elliptic to slightly obovate, widest in ± middle, 12.3–21.4 by 2.8–5.7 cm, 2.4–4 times as long as wide, pergamentaceous to slightly coriaceous, base cuneate, margin serrulate, with glands abaxially in the teeth, recurved, apex (acuminate to) cuspidate, lower surface bluish green, venation slightly raised above, raised below, secondary veins 10–14 pairs, intercalary nerves mainly absent, higher order nerves reticulate. Inflorescences axillary, cymose, less than 1 cm long, square, slightly hairy; staminate flowers with few together, pistillate ones single; bracts triangular to ovate, c. 1.5–2 by 1–1.8 mm, margin hairy to slightly hairy outside. Staminate flowers only seen in bud; pedicel c. 20.5 mm long above abscission zone, round, glabrous; calyx c. 4.8 mm deep, lobes ovate, outside and inside glabrous, on each lobe a round gland near apex outside; petals oblong; stamens c. 20, anthers dorsifixed, c. 1 by 1 mm. Pistillate flowers c. 9.5 mm diam; pedicel c. 13.5 mm long above abscission zone, round to ribbed, glabrous; calyx c. 4.7 mm deep, lobes ovate, c. 4.3 by 3.7 mm, glabrous, on each lobe a round gland near apex outside; petals not seen; ovary ovoid, c. 5 by 3.5 mm, echinate with stump, apically slightly thickened soft spines, glabrous, stigmas not seen. Fruits outside with soft non-confluent spines, glabrous, ripe purple or red; calyx lobes hardly enlarged, 4–5 by 3.8–4 mm; wall woody, c. 1.2 mm thick, exocarp detaching or not; columella 9–10 mm long. Seeds c. 9 by 8 by 7 mm.

Distribution — Endemic in W Borneo ( Brunei, Sarawak).

Habitat & Ecology — Primary lowland dipterocarp forest to secondary forest, usually on hill slopes and ridges; soil: sandy clay to sandstone and shale. Altitude: 20– 400 m. Flowering: April, May, August, September; fruiting: January, April, June, August to October.

Uses — Roots are boiled together with roots of Psychotria cf. crassifolia Miq. ( Rubiaceae ), mixture is drunk and known as the medicine ‘Ubat sara’.

Note — This species, formerly united with D. denticulatus , is here reinstated. It only occurs locally in NW Borneo and differs from the typical D. denticulatus . Typical are the echinate fruits and the sepals that are only slightly hairy along the margin and generally show a round glandular thickening on every sepal lobe.