Tree 6–30 m. high, with flat or rounded spreading crown; bark grey to dark brown, scaly; branchlets glabrous. Leaves: rhachis with petiole 4–32 cm. long or more; leaflets (mature) 2–5(–6) pairs, petiolulate, elliptic to ovate-elliptic, mostly 5–15 cm. long, 2.8–6.9(–8.5) cm. wide, obtusely pointed to ± acuminate at apex. Inflorescences paniculate, with racemose branches 3–13 cm. long, rarely (? casually and by reduction) inflorescence simply racemose. Flowers sweetly scented, with hypanthium 0.3–0.6 cm. long. Sepals shortly and densely velvety-pubescent or -puberulous outside, broadly obovate-elliptic to rotund, 2 outer 6–9 mm. long, 5–7 mm. wide, 2 inner 7–11 mm. long, 6–10 mm. wide. Large petal 1.1–2 cm. long, white or greenish-white, with pinkish-crimson streak down centre, with a rather long claw suddenly widened into a bilobed lamina 0.7–1.1 cm. wide. Stamens 7 fertile, with ± pubescent filaments. Style ± pubescent below. Pods straight, 10.5–20.5 cm. long, 5.5–8.5 cm. wide. Seeds black, ellipsoid or oblong-ellipsoid, 1.6–3 cm. long, 1.1–2.1 cm. wide, with an orange cup-shaped basal aril.