Biennials or sometimes annuals. Stem 10-55 cm tall, erect, not rooting at nodes, with 0.4-1 mm ± patent glandular trichomes. Stipules ovate, distinct. Leaves opposite; petiole with 0.3-0.5 mm retrorse not appressed nonglandular trichomes and 0.4-2.4 mm patent glandular trichomes; leaf blade 3-9 cm, palmately divided, pilose with ± appressed glandular trichomes; segments 5, rhombic, with a petiolule on middle segment 0.2-0.4 × as long as its segment, 16-46-lobed in distal half, ratio of second sinus/middle segment length = 0.26-0.5. Cymules solitary, 2-flowered; peduncle 1-6 cm. Pedicel 0.5-2 cm, with 0.4-1.5 mm patent glandular trichomes and 0.3-0.5 mm retrorse not appressed nonglandular trichomes; bracteoles lanceolate. Sepals 6-8 mm, mucro 1.8-2.5 mm, ratio of mucro/sepal length = ca. 0.3, outside with 0.3-0.5 mm ± patent nonglandular trichomes and 0.4-3.2 mm patent glandular trichomes, inside glabrous. Petals purplish, 7.5-9.7(-10.4) mm, erect to patent, glabrous, apex rounded. Staminal filaments pinkish, lanceolate with an abruptly narrowed apex, glabrous; anthers purplish, 0.4-0.6 mm. Nectaries 5, hemispheric, glabrous. Stigma pinkish. Fruit 1.9-2.3 cm, erect when immature; mericarps reticulate, ridges sparse and scarcely anastomosing in basal half but denser apically and forming 1 or 2(or 3) overlapping collar-like keels at apex, without a basal callus, glabrous or sometimes with ca. 0.2 mm nonglandular trichomes, small glands, or both; rostrum 1.7-1.9 cm, with a 4-5 mm narrowed apex; stigmatic remains 1-1.3 mm. Seeds 2.1-2.2 mm. Fl. Apr-Jun, fr. May-Aug. 2n = 64.
"Weak annual or biennial with branched, spreading, villous or villosulous stems to 6 dm; lvs 3–5-cleft to the base, at least the terminal segment evidently petiolulate, all segments pinnately lobed or cleft; peduncles from most of the upper nodes, mostly 2-fld; sep 7–9 mm, shortly aristate, erect at anthesis; pet 9–13 mm, bright pink or red-purple, entire, long- clawed; carpel-bodies (unlike our other spp.), disarticulating from the beak but tending to remain attached for some time to the stylar column by a pair of elongate, subapical filaments, the proper beak separating from the stylar column ± as in other spp.; 2n=32, 64. Damp rich woods; widespread in the Old World (esp. Eurasia) and widely naturalized in our range. May–Sept. (Robertiella r.)"