Flower:

Irregular 5-petaled blue-violet flower ½ to nearly 1 inch (to 23 mm) long at the end of a long naked stalk usually held well above the leaves at peak bloom. The 2 lateral petals have small tufts of white hairs at the base (bearded), the hairs typically under 1 mm long and club shaped with a conspicuously swollen tip. The lower petal is white at the base with dark purple veins radiating from the center, and forms a short spur at the back.

Sepals are narrowly triangular to lance-linear, pointed at the tip, and hairless.

Leaves and stems:

Leaves are all basal; color is light to medium green. Mature leaves are up to 4 inches (to 10 cm) long, to 2½ inches wide, heart-shaped with a blunt or pointed tip. Leaf edges are scalloped or have blunt serrations, with fewer, shallower teeth near the tip; surfaces are hairless, sometimes sparsely hairy on the upper surface. Leaf stalks are hairless.

Fruit:

Both petalled (chasmogamous) and petal-less, self-pollinating (cleistogamous) flowers produce fruit, in an ovoid capsule up to about ½ inch (10 to 15 mm) long, initially green, erect when mature and drying tan.

Seeds are dark brown to dark reddish-brown, 1.4 to 1.9 mm long.

Notes:

Marsh Blue Violet can thrive in both sun or shade as long as the site is moist. The plant structure at peak bloom, with flowers rising well above the leaves, is similar to Northern Bog Violet (Viola nephrophylla). Prior to this stage it may more closely resemble Common Blue Violet (Viola sororia). All 3 species have only basal leaves and bearded blue-violet flowers, but the hairs on V. cucullata are distinctly different—short and stubby compared to the others. V. cucullata hybridizes with several other violets, but violet hybrids are not well documented in Minnesota.