Alangium subcordatum 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 : 45

19. Alangium subcordatum W.J.de Wilde & Duyfjes , sp. nov.

Distinct from all other Alangium species by the combination of the following characters: stout habit; densely hairy twigs leaf bud and inflorescences; petiole slender, 2‒4.5 cm long; lamina broad, 14‒27 by 7‒12 cm, with broadly rounded or shallowly cordate base;filaments glabrous. — Type: K. J. White NGF 10471 (holo SING SING0208284 ;iso L L.2497994, LAE), Papua New Guinea, Morobe Prov., Oomsis near Lae , 300 ft., 3 Mar. 1959, fl. & fr .

Etymology. The specific epithet refers to the leaf base.

Tree 10‒40 m tall; twigs brown, 4‒6 mm diam, in apical portion densely hairy, the hairs rusty-brown, towards the apex grey, c. 0.5 mm long; leaf bud curved, with similar hairs. Leaves: petiole 2‒4.5 cm long; lamina drying (dark) greenish brown, glabrous, except veins below, broadly elliptic, 14‒27 by 7‒12 cm, base symmetric,broadly rounded or slightly cordate, apex acute-acuminate; veins pinnate, 8‒15 on each side, (faintly) loop-veined; tertiary venation (reticulate-)scalariform. Inflorescences hairy as the twig and leaf bud, single, few-branched, 1‒3-flowered; peduncle 5‒10 mm long. Flowers hairy (hairs c. 0.5 mm long); pedicel 2‒3(‒8) mm long; corolla in bud ± woody, 10‒13 mm long, not swollen at base, apex subobtuse; ovary and calyx 4‒7 mm long, faintly c. 10-ribbed; limb not spreading, 1‒2 mm long, at margin 3.5‒5 mm wide, margin faintly 10-lobed; petals 6, inside glabrous, 10‒13 mm long; stamens 6, filament 2.5‒3 mm long, not thickened, glabrous, anther 9‒10 mm long, connective glabrous; style densely hairy (except towards base), 10‒12 mm long, stigma narrowly conical. Fruit 1 (or 2?) per infructescence, ripening colour not recorded, (yellow-)brown hairy, ovoid(-ellipsoid), c. 30 by 20‒22 mm, not ribbed; calyx remnant short, 2‒2.5 by 5‒6 mm.

Distribution ― Papua New Guinea (Morobe Prov.), known from 3 collections.

Habitat & Ecology ― Primary rain forest, on slope and flat ground; 100‒150 m altitude; flowering in January and March; fruiting in March and September.

Field-notes ― Strongly buttressed; bark grey brown or light grey, smooth, exfoliating in rounded flakes leaving a sculptured surface; fruit laterally compressed.

Proposed IUCN (2012) conservation assessment — Data Deficient (DD), although there is concern as the species has been collected only thrice in a restricted area in lowland rain forest.

Additional specimens studied. PAPUA NEW GUINEA, Morobe Prov., Kairo & Streimann NGF 25578, Oomsis, 300 ft., 24 Sept. 1964, fr.; Hartley TGH 11351, N of Lae , between Rivers Busu and Butibum, 4 Mar. 1963, 500 ft., fr .