Viola palustris

Perennial herb.

3–8 cm high.

The leaves and scape emerge directly from the rhizome. The rhizome is stoloniferous.

There are typically three or four leaves. The lamina is simple, 2–4 cm wide in early summer and larger later in summer, reniform, wider than its length, rounded at the apex, light green, glabrous on both sides and crenate.

The scape is delicate. The prophylls are at the middle of the scape or lower. The flowers are bisexual, drooping and zygomorphic. The calyx and corolla are five-leaved. The corolla (1–1.5 cm) is light violet. The lowest petal has a saccate spur that protects the spur-like appendage of the two lowest stamens. The lowest petal is 8–10 mm in size. The spur is almost as long as the appendages of the calyx, thin and of the same color as the rest of the corolla.

The fruit is a capsule with three locules.