Flowering stems creeping, 0.5-1.5 dm. Leaves opposite; blade obovate or orbiculate, 1-3 cm, margins prominently glandular, coarsely crenate apically. Flowers: sepals deltate to lanceolate, 4-4.5 mm, apex subobtuse; petals erect basally, recurved at tips, white to pink, ovate, 8-11 mm, apex shortly mucronate. Carpels erect in fruit, connate basally.

Flowering summer. Rocky places, roadsides, fields, waste places; 0-2000 m; introduced; Nfld. and Labr. (Nfld.), N.S., Ont., Que.; Colo., Conn., Ill., Ind., Maine, Mass., Mich., N.J., N.Y., Pa., Vt.; c Asia (Caucasus).