Small tree up to 10 m. high. Young branches and inflorescence-axes thinly to fairly densely covered with dark brown, appressed or ascending hairs. Leaves: petiole 1.2–10 cm.; lamina ± narrowly elliptic, 5–21 cm. long, 2.5–8 cm. wide, 2.5–4 times as long as broad, cuneate or slightly rounded at the base, obtuse to rounded at the apex, coriaceous, with a reticulate venation prominent on both surfaces; both surfaces glabrous, at least at maturity. Flowers in fairly lax terminal and axillary racemes aggregated to form a terminal panicle up to 25 cm. long; bracts as in B. macrocalyx but usually narrower, up to 5 × 2 mm.; pedicels 5–15 mm.; bracteoles suborbicular or ovate, 2–3.5 mm. long, 1.5–2.2 mm. wide, inserted immediately beneath the calyx and opposite each other or slightly asymmetrically placed. Calyx 11–14 mm. long, densely pubescent with appressed dark brown hairs, at anthesis splitting to the base down 2 sides into 2 sub-equal halves which fall separately. Petals pale pink with a yellow blotch near the base; standard 16–21 mm. long; wings 16–19 mm. long; keel-petals 13–16 mm. long. Stamen-filaments densely hairy; anthers 2–2.5 mm. long. Ovary brown tomentose with a glabrous style. Pods 7–12 cm. long, 1.3–1.9 cm. wide, strongly curved upwards above the middle, glabrous at maturity, brown.