Perennial herbaceous plant, 20-40 cm tall. The rhizome is thick, ligneous, covered with rusty-brown scales. A stalk with shortened internodes and a rosette of basal leaves develops after the appearance of the first flowers. The basal leaves are whole, broadly ovate, with a kidney-shaped or round-heart-shaped base, along the edge with shallow indentations, bare or weakly pubescent with short hairs, located on long petioles, with ovate-lanceolate stipules with a whole or notched-dentate edge.
Single flowers . In the spring, in the axils of the basal leaves, hazmogamous, mostly sterile flowers appear. A little later, stems that appear after the first flowers grow cleistogamous , fertile flowers. 5 sepals, large, lanceolate, of equal length. Sterile flowers are zygomorphic (irregular), have five light purple unequal free petals. Petals are rounded ovoid, two lateral at the base pubescent, inclined to the lower lobe, lower lobe naked, larger than the others, the upper two bent upward. Kleistogam flowers are small, inconspicuous, similar to unopened buds. Five stamens. Ovary superior, single-ovary. The column is short, simple, the stigma is thickened, with the nose bent down.
The fruit is trihedral, loculicidal (nest bursting), glabrous, oblong-ovoid capsule , when ripe, opens with three wings and throws out seeds.
Flowering in April - June.
It occurs in the Mediterranean, temperate and suboceanic climatic zones of Europe. Shade-tolerant, moisture-loving forest plant, grows in deciduous forests (mainly oak forests) and mixed forests, bushes.
