A perennial, robust, much branched herb, sometimes woody at base, 2(—4) m tall, lower part of stem sometimes with aerenchyme, pseudo-aerophores present in inundated conditions, normally with appressed or spreading hairs. Leaves alternate, light green, may turn red upon aging, narrowly lanceolate to ovate, up to 15 cm long, 4 to 40 mm wide, densely pubescent both sides, attenuate at base and apex, 12 to 22 veins each side of midrib, short petiole; sepals 4, ovate or lanceolate, 8 to 13 mm long by 1 to 7.5 mm wide. Flowers solitary in axils of leaves and at terminals; petals 4, pale to bright yellow, 1 to 2 long and 4 to 17 mm wide, broadly ovate and may be emarginate at apex; sepals 4, 8, to 15 cm; stamens 8, filaments 1 to 4 mm long; anthers 1 to 4 mm long, white, hairy, sunken nectary surrounding base of each epipetalous (and shorter) stamen; style 1.5 to 3.5 mm long with stigma subglobulose and shallowly 4-lobed. Capsule 1.7—4.5 cm x 0.2—0.8 cm, terete, thin-walled, pale brown, 8 darker ribs, irregularly splitting, pedicel up to 10 mm long. Seeds pluriseriate in each cell, free, rounded, raphe as long as the seed.

Carminative and vermifuge (decoction of leaves); analgesic (plant); laxative (pulped and boiled plant).

PROSEA (Plant Resources of South-East Asia) Foundation

Used against ulcerations of the nose and rheumatic pains (plant); or poulticing many complaints, including headache, orchitis and swollen glands (leaves); for diarrhoea and nervous diseases (decoction of leaves).