Outer sepals 1·5–1·8 × 1·5 mm., subcircular, inner 1·5 × 1 mm., elliptic, all glabrous or sparsely pubescent.
Stamens with filaments 1·8 mm. long; staminodes 0·5 mm. long in male flowers.
Inflorescence up to 24 cm. long, unbranched, sparsely pubescent to glabrous.
Flowers white or greenish, in few-flowered subsessile glomerules or short cymules with rhachis 0·5–1 mm. long; pedicels up to 3 mm. long.
Large shrub or small tree up to 3–7 m. tall (but see note below); branchlets appressed-pubescent when very young, soon glabrescent, usually pale with rather prominent whitish lenticels.
Leaves 3-foliolate; petiole up to 7 cm. long, pubescent to nearly glabrous; terminal leaflet usually 11/2 times as long as the lateral ones; petiolules up to 15 mm. long but usually much shorter in the often subsessile lateral leaflets; lamina of terminal leaflet up to 15·5 × 6 cm., elliptic to narrowly elliptic, papyraceous (when young) to subcoriaceous, nearly glabrous except for occasional tufts of hairs in the axils of the primary and sometimes of the secondary nerves on the under surface, apex usually acuminate, margin rather remotely serrate or serrulate or crenate-serrulate, base cuneate to broadly cuneate (rarely slightly narrowed, perhaps due to hybridization with A. alnifolius); lateral nerves 8–10 pairs.
Fruit 6 mm. in diam., subglobose, minutely pubescent, 1 or 2 cocci developing.
Ovary 2-lobed, pubescent; style 2 mm. long, 2-fid.
Filaments 1.8 mm. long; staminodes 0.5 mm. long.
Flowers usually ± large for the genus; outer sepals elliptic, 1.5 mm. long, 1 mm. wide, inner subcircular 1.5–1.8 mm. long, 1.5–3 mm. wide, glabrous or slightly pubescent; petals white or greenish yellow, spathulate, 1.5 mm. long, 1 mm. wide.
Fruits yellow or red, of 1–2 mericarps, each subglobose or obovoid, 6–6.5 mm. long, 5 mm. wide, minutely pubescent or glabrous.
Ovary 2-lobed, pubescent; style 2 mm. long.
Inflorescences unbranched or rarely branched, 5–17(–24) cm. long, including peduncle 1–8 cm. long, glabrous or spreading pubescent, the 1–few-flowered cymules usually well spaced; cymule stalk and rhachis 0.5–1 mm. long, pedicels 1–3 mm. long.
Shrub, often straggling or scrambling or a distinct climber, less often a small tree (see note), (0.6–)1.5–4.5(–6) m. tall or long; stems very lenticellate, pubescent when young then glabrescent or ferruginous velvety.
Leaves trifoliolate; petiole 2–7 cm. long, glabrous to densely pubescent; petiolules 0.2–1.5 cm. long or lateral leaflets often ± sessile; leaflets very discolorous, drying leaden grey above with the venation yellow and pale greenish or often bright brownish beneath, elliptic, oblong, rhombic or narrowly oblanceolate, 4–15.5 cm. long, 2–6 cm. wide, acute or acuminate at the apex, cuneate at the base, the laterals mostly very asymmetric, subentire to ± remotely serrate, crenate-serrate or coarsely serrate, glabrous to densely almost velvety ferruginous hairy and with tufts of hairs in axes of lateral nerves beneath; lateral nerves in 8–10 pairs, venation raised and reticulate above (impressed in life fide Milne-Redhead & Taylor) and strongly so beneath.