Description from Flora of China
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.