Herbs perennial, erect, or ascending proximally. Rhizomes long. Leaves alternate. Panicles terminal, pyramidal, consisting of cincinni, involucral bracts and bracts caducous. Flowers actinomorphic. Sepals free, boat-shaped. Petals free, anterior one narrower, all blue or purple, oblong, obovate, or elliptic. Fertile stamens 3, anterior, middle one inserted opposite petal, with slightly smaller anther and slightly shorter filament; filaments glabrous; staminodes 3, posterior; antherodes 2-lobed. Ovary 3-loculed; ovules 4--8 per locule. Capsule 3-valved, cylindric. Seeds 4--8 per valve, rugose; hilum linear.

Seven species: from the Himalayas to Indonesia (Borneo) and the Philippines; two species (endemic) in China.