Alangium guadalcanalense W.J.de Wilde & Duyfjes, 2017

de Wilde, W. J. J. O. & Duyfjes, B. E. E., 2017, The species of Alangium section Rhytidandra (Alangiaceae), Blumea 62 (1), pp. 75-83 : 78-79

5. Alangium guadalcanalense W.J.de Wilde & Duyfjes , sp. nov.

Resembling Alangium polyosmoides (F.Muell) Baill. subsp. tomentosum (F.Muell) W.J.de Wilde & Duyfjes but differing in its filaments completely fused with the 3 mm long basal corolla tube (base of filaments slightly adnate to petals in A. polyosmoides subsp. tomentosum ). ― Type: Gafui & collectors BSIP (holo L L.2183210; iso BSIP n.v.), Solomon Isl., West coast of Guadalcanal Isl., Kambi Hill , 600 m alt., 14 June 1968, fl .

Etymology. The specific epithet ‘ guadalcanalense ’ refers to the collection locality, Guadalcanal Isl.

Tree c. 6 m tall; twigs greyish brown, 2–4 mm diam, densely greyish brown-hairy, hairs 0.5(‒1) mm long. Leaves: petiole 0.5‒0.7 cm long; lamina drying brownish green, hairy at both sides (upper side partly late glabrescent), ovate(-elliptic), 10‒12 by 4.5‒6.5 cm, base strongly asymmetric, rounded to short acuminate, apex acute-acuminate; veins 5‒7 at each side, tertiary venation reticulate or faintly scalariform, domatia absent. Inflorescences densely hairy, solitary peduncled (compound) cymes, 4‒7-flowered; peduncle 6‒7 mm long. Flowers densely hairy as the twigs; pedicel 1‒2 mm long; corolla in bud 9‒10 mm long, base not swollen, apex narrowly obtuse; ovary and calyx 3‒4 mm long, not ribbed, greyish brown-hairy; limb 1.5‒2 mm long, not spreading, at margin 2‒2.5 mm wide, with 5 small lobes; petals 5, inside hairy, 9‒12 mm long, at base for 3‒4 mm connate into a tube; stamens 5; filament (3‒) 4 mm long, completely adnate to the hairy tube of the corolla, anther c. 6 mm long, inserted in the calyx at apex of tube, connective glabrous; style 6‒7 mm long, hairy, stigma lobes c. 1.5 mm long. Fruit not known.

Distribution ― Solomon Isl. (Guadalcanal Isl.), known only from the type.

Habitat & Ecology ― Well drained primary forest, ridge top; c. 600 m altitude; flowering in June.

Field-notes ― Bole straight but leaning; bark surface grey, smooth.

Note ― In general appearance reminiscent of A. polyosmoides subsp. tomentosum from Australia but markedly different in the filaments completely fused with the corolla tube, rendering the thecae sessile in the tube.