Description from Flora of China
Mairella H. Léveillé.
Herbs perennial, scapose; pubescence of simple hairs. Roots stout, vertical. Stems short, sometimes branched; axis sometimes elongated into a scape. Leaves often subsessile and forming a basal rosette; leaf blade entire, sinuate, or dentate, often undulate, sometimes reduced. Flowers in leaf or bract axils; peduncle absent; bracts membranous. Flowers actinomorphic, 5-merous. Pedicel sometimes elongated. Calyx rotate-campanulate, deeply lobed. Corolla campanulate, lobed. Stamens inserted in distal part of corolla tube, included; filaments slender, pubescent, at least basally; anthers oblong, dehiscing longitudinally. Disc evident, lobed. Ovary 2-locular; ovules numerous. Stigma slightly expanded. Fruiting calyx somewhat enlarged. Fruit yellow or orange, globose or ovoid juicy berry, becoming unilocular. Seeds compressed, reticulate; embryo curved, peripheral.
About four species: SW Asia, Europe; one species in China.