Shrubs, entirely glabrous. Leaves opposite, more or less distichous, petiolate, ellipticovate,
curvipinnate, glabrous. Inflorescences centrifugal pseudoracemes, spikes or sometimes
contracted into peduncled umbels; flower buds constricted to a neck, clavate with rounded
apex; flowers bracteate, bracteolate, actinomorphic, sympetalous, 5- or 6-merous; each flower
subtended by 3 unequal scale-like partially connate bracteoles, fused completely with bracts
and not enclosing ovary. Calyculus tubular, truncate or lobed. Petals 5 or 6, connate; tube with
distinct angular shoulders; lobes reflexed. Stamens 5 or 6; filaments subterete; anthers adnate
or basifixed, linear or elliptic-ovate, isothecate, elevatilobate, without sterile apex. Ovary oblong,
bearing an entire calyx-rim, smooth; style articulate above the base or not; stigma capitate or
broadly elliptic-ovate. Fruits urceolate or globose, rugulose or muricate with or without collar
and stylar stub.
South and South-East Asia, ca 25 species; 3 in India.
KEY TO THE SPECIES
1a. Young internodes margined on three sides; old nodes meristematically knotty; leaves decurrent;
inflorescence ramiflorous; flower buds spathulate; flowers 5- merous; corolla-lobes reflexed
and coiled; anthers with sterile apex; ovary subturbinate, faintly tubercled; endosperm without
thickened pads, but horned
b. Young internodes not margined, old nodes not meristematically knotty; leaves not decurrent;
inflorescence axillary; flower buds clavate with rounded apex; flowers 6- merous; corolla-lobes
reflexed, not coiled; anthers without sterile apex; ovary oblong, smooth; endosperm with
thickened pads, hornless
2
2a. Lateral nerves distinct on either surfaces; midrib evanescent towards apex; petioles flattened
adaxially; flowers prominently shouldered at angles; corolla-tube splitting up to two-third the
length; anthers planilobate; fruits with collar and stylar stub, rugulose; endosperm with 6
narrowly elliptic thickened pads
b. Lateral nerves obscure on either surfaces; midrib extending up to tip; petioles sulcate adaxially;
flowers faintly shouldered at angles; corolla-tube splitting up to middle; anthers elevatilobate;
fruits without collar and hemispherical stylar stub, muricate; endosperm with 4 thickened
pads
