Dimorphocalyx trichocarpus (Airy Shaw) Welzen & Oostrum, 2015

8. Dimorphocalyx trichocarpus (Airy Shaw) Welzen & Oostrum View in CoL , comb. nov. — Map 1

Dimorphocalyx luzoniensis Merr. var. trichocarpus Airy Shaw (1975) View in CoL 96. — Type: S (Anderson) 20974 (holo K; iso L), Malaysia, Sarawak, First Divi- sion, Bidi, Bau.

Trees, dbh to 12 cm; flowering branches 3–4.5 mm diam, yellowish when dry, slightly lenticellate. Indumentum of light yellow hairs. Outer bark grey, smooth. Stipules caducous, base at least 4.5 mm wide, slightly hairy outside, especially in the thicker centre, stiff. Leaves: petiole 25–36 mm long, 1.2–3 mm diam, deeply furrowed to flattened above, slightly pulvinate basally and apically, glabrous; blade slightly ovate to slightly obovate, widest in ± middle, 22–33 by 9.4–14.3 cm, c. 2.3 times as long as wide, papyraceous, base rounded, margin laxly serrulate, with glands abaxially in the teeth, recurved, apex acuminate, venation flat to slightly sunken above, raised below, secondary veins 13–16 pairs, higher order nerves reticulate. Staminate inflorescences and flowers not seen. Pistillate inflorescences axillary, short, racemose, one flower developing into fruit; flattened to angular, hairy; most bracts broken, one leaf-like, c. 12 by 7 mm, others ovate, c. 6 by 4 mm, outside hairy, inside glabrous. Young fruits smooth, densely hairy, green; pedicel c. 24 mm long above abscission zone, hairy; sepals enlarging, unequal, 14–17.5 by 11–15 mm, glandless, outside and inside hairy; petals caducous; disc glabrous; style c. 1 mm long, densely hairy, stigmas c. 5 mm long, basal 1.5 mm not split, hairy beneath. Seeds not seen.

Distribution — Borneo (endemic in Sarawak).

Habitat & Ecology — At base of limestone hill on limestone rocks with intervening igneous derived soil. Altitude: c. 100 m. Fruiting: April.

Note — Only known from the type, which is very distinct by its very large leaves, rather long petioles, hairy, enlarging sepals, hairy fruits and glabrous discs. Because of its distinctiveness this taxon is raised to species level.