Flower:

Irregular 5-petaled pale blue to purple flower up to about ½ inch (to 15 mm) long at the end of a naked stalk held above the leaves at peak bloom. Petals are white at the base; the 2 lateral petals lack tufts of hair at the base (beardless). The lower petal has dark purple veins radiating from the center and forms a thick spur at the back.

Sepals are lance to narrowly egg-shaped, blunt to pointed at the tip, and hairless.

Leaves and stems:

Leaves are all basal, forming a rosette; color is medium to dark green. Mature leaves are up to 2 inches (to 5 cm) long and nearly as wide, heart-shaped with a pointed tip, and a deep, narrow gap (sinus) between the basal lobes; the lobes often touch or overlap. Leaf edges are scalloped or have blunt serrations; the upper surface is sparsely to moderately hairy, the lower surface hairless. Leaf stalks are hairless.

Fruit:

Both petalled (chasmogamous) and petal-less, self-pollinating (cleistogamous) flowers produce fruit, in an ovoid capsule up to about 1/3 inch (4 to 8 mm) long, initially green, erect when mature and drying tan with purple splotches. Seeds are light orange-brown, 1.5 to 2 mm long.

Notes:

Distinguishing the blue/purple violets can be challenging. Things to look at are whether the flowers are bearded, whether there are leaves on the flowering stem, whether leaves are hairy and to what degree, and the general shape of the leaves. Great-spurred Violet has fairly distinctive leaves that are basal only, hairy only on the upper surface and have the deep, narrow sinus at the base, the 2 basal lobes often touching or overlapping even when the leaves are flattened. It is also the only beardless blue/purple violet in Minnesota with heart-shaped leaves, though violets are known to hybridize like crazy and it's possible some offspring of a mixed marriage may have some or all of these characteristics. Habitat can be another indicator, with Great-spurred Violet typically found in cool, moist woods and ravines, preferring rich organic soil, often growing in moss-covered crevices or on rotting logs.