Erect rheophytic herb with watery latex in all parts. Leaves whorl of three, sometimes opposite near the top; blade linear-oblong to linear-lanceolate, membranous-coriaceous, base acute to attenuate, apex acute; margins entire, sometimes with short scattered hairs. Inflorescences racemes with condensed rachis, subumbelliform, often paniculate, extra-axillary; flower bud ovoid. Calyx lobes 5, green with reddish brown apex, ovate-lanceolate, apex acute, inside with one small gland between each pair of lobes. Corolla white, rotate; lobe slightly reflexed, oblong-lanceolate, apex obliquely obtuse or retuse, margin and apex revoluted. Corona 5, half as high as anther, erect, joined at base to form a flat, fleshy, shallow cup; lobes triangular-ovate, apex acute-blunt, white. Anthers 5, fleshy, oblong, yellowish white. Ovary 2, glabrous. Follicles 1, linear-lanceolate in outline.