Description from Flora of China
Herbs annual, (7-)15-55(-75) cm tall, eglandular, pubescent, with minute, twisted, simple trichomes mixed with straight rigid ones to 0.5 mm. Stems erect, often simple, branched above. Middle cauline leaves sessile, linear or rarely lanceolate-linear, 1-4(-5) cm × 1-2(-3) mm, base attenuate, margin entire, ciliate and often pubescent with simple rigid trichomes, apex acute. Fruiting pedicels divaricate or rarely ascending, straight, slender, (4-)5-10(-12) mm, pubescent. Sepals narrowly oblong, 2.5-3.5 × 0.5-0.8 mm. Petals lilac or purplish, narrowly oblanceolate, 3-5 × 0.6-1 mm, attenuate to a clawlike base to 1.5 mm, apex obtuse. Filaments of median stamens 2.5-3.5 mm, united; filaments of lateral stamens 2-2.5 mm; anthers ovate, 0.4-0.5 mm, apiculate. Ovules 30-50 per ovary. Fruit (1.8-)2.5-4 cm × 0.6-0.8 mm, glabrous, straight, erect or slightly ascending, torulose, terete, midvein prominent; style 0.4-0.8(-1) mm; stigma slightly lobed. Seeds brown, ovate, 0.5-0.8 × 0.4-0.5 mm, not margined; cotyledons obliquely incumbent. Fl. Jun-Jul, fr. Jul-Aug.
Grassy slopes, river banks; 900-3300. Gansu, Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Qinghai, Shanxi, Xinjiang [Mongolia, Russia (Far East, Siberia)].