Viola rotundifolia is a low perennial herb, colonial from a long rhizome covered with old leaf bases, otherwise stemless.
Leaves tufted, basal, early leaves to 3 cm long, nearly as wide, broadly heart-shaped, finely blunt-toothed, stalks hairy, tending to become prostrate later, summer leaves to 12 cm, rounded with deeply lobed base, lobes overlapping.
Flowers yellow, developing with leaves, bilaterally symmetric, 5 parted, side petals bearded, 3 lower petals with brown veins; closed flowers later in season on short, leafless stolons, sometimes partly below ground.
Fruit a capsule to 0.8 cm, dotted with purple, seeds cream-white; blooms April-May.
Wetland status: FAC+.
Frequency in NYC: Very infrequent.
Habitat: Rich moist woods.
Notes: Host to larvae of the great spangled fritillary butterfly, Speyeria cybele (Nymphalidae), (Pyle 1981).