Calpocalyx

Shrubs or small trees; trunk much branched; branchlets glabrous. Leaves bipinnate, consisting of a single pair of pinnae each bearing 3-7 pairs of opposite leaflets with basal leaflet often single; leaflets elliptic-oblanceolate with asymmetric base. Inflorescences with flowers crowded in dense, narrowly cylindric spikes on long peduncles arranged in ample terminal, or sometimes axillary panicles. Flowers bisexual or unisexual by abortion. Calyx campanulate, 5-lobed. Petals 5, cohering in lower half. Stamens 10; filaments filiform, arising at base of petals, free or slightly coherent at base; anther connective ending in a caducous gland. Ovary +/- stipitate, oblong, pubescent, arising in bottom of receptacle; ovules 4 or 5; style slender, ending in a tapering stigma. Pod dehiscing with 2 glabrous, triangular, woody valves.