Description from Flora of China
Alaida Dvorák; Andreoskia de Candolle; Dimorphostemon Kitagawa; Hesperidopsis (de Candolle) Kuntze.
Herbs annual, biennial, or perennial. Trichomes unicellular, eglandular, simple, straight or crisped, sometimes mixed with multicellular, multiseriate glandular ones. Stems erect or ascending, simple or branched. Basal leaves petiolate, rosulate or not, simple, entire, dentate, pinnatifid, or pectinate-pinnatifid. Cauline leaves petiolate or sessile, similar to basal. Racemes ebracteate, elongated in fruit. Fruiting pedicels ascending or divaricate. Sepals ovate, not saccate. Petals white, pink, or purple; blade broadly obovate, obcordate, spatulate, or oblanceolate, apex obtuse or emarginate; claw subequaling sepals or longer. Stamens 6, tetradynamous; median filament pairs united, sometimes free and toothed below anther or expanded to base, dilated at base; anthers ovate or oblong, often apiculate at apex. Nectar glands 4, lateral, 1 on each side of lateral stamen; median glands absent. Ovules 7-60 per ovary. Fruit dehiscent siliques, linear, terete or latiseptate; valves with a prominent midvein and often distinct marginal veins, glabrous or glandular, torulose; gynophore obsolete, rarely to 1 mm; replum flattened; septum complete; style obsolete or to 3 mm; stigma capitate, slightly lobed, rarely prominently lobed and subdecurrent. Seeds uniseriate, winged, margined, or wingless, oblong or ovate, plump or slightly flattened; seed coat reticulate, not mucilaginous when wetted; cotyledons accumbent or incumbent.
Dontostemon is separated from Dimorphostemon only by having united (vs. free) median staminal filaments. However, the union of filaments evolved independently within several other genera in the Brassicaceae, and the separation of these two genera is artificial.
Eleven species: China, India, Japan, Kashmir, Kazakhstan, Korea, Mongolia, Nepal, Russia, Sikkim, Tajikistan; 11 species (one endemic) in China.