Description from Flora of China
Annual herbs; stems stellate or hairy with other types of hairs. Stipules minute, caducous; leaf blade simple, basal veins 3, margin dentate or serrate, stellate hairy. Inflorescence axillary, cymose, 1-3-flowered. Flowers bisexual. Sepals 5, narrowly lanceolate. Petals 5, yellow, obovate. Stamens usually 15, in 5 groups of 3 alternating with staminodes; staminodes 5, spatulate-linear. Ovary densely tomentose or glabrous, 3-celled; ovules many per locule; style subulate; stigma truncate, slightly 3-lobed. Capsule cylindric, 3-valved. Seeds many.
One species: China, Japan, Korea.