Flower:

 Single irregular 5-petaled flower at the end of a naked stem that may or may not rise above the leaves. Flowers are white with a greenish throat, up to ~½ inch (≤ 12 mm) long. The upper two petals are typically bent back, the two lateral petals are usually hairless, sometimes with a few short hairs at the base (sparsely bearded), the lower petal is hairless, has purple veins near the base, and forms a short rounded spur at the back.

The 5 sepals around the base of the flower are hairless, the two lower largest, lance to egg-shaped, rounded to blunt or rarely pointed at the tip, and have a short extension at the base (auricle) that is usually rounded along the end and does not elongate in fruit.

Leaves:

 Leaves are all basal, held spreading to ascending, mostly egg-shaped to nearly round in outline, rounded to blunt at the tip, shallowly to deeply heart-shaped at the base. Largest leaves are up to about 2¾ inches (73 mm) long, longer than wide to about as long as wide.

Both surfaces are green and hairless, the lower somewhat paler than the upper. Edges have shallow teeth and lack a fringe of hairs. Leaf stalks are hairless or sparsely hairy. In mid to late summer above ground stems (stolons) are produced that have multiple nodes each with a leaf and fruiting capsule. The stolon ends in a new plantlet.

Fruit:

Both petalled (chasmogamous) and petal-less, self-pollinating (cleistogamous) flowers produce fruit, in a hairless, ovoid capsule that is initially nodding, becoming erect just before splitting into 3 sections and releasing its seed. Chasmogamous capsules are typically green. Chasmogamous flowers bloom in spring. Cleistogamous flowers are produced all summer into fall on erect to ascending stalks shorter or longer than the leaf stalks; capsules are ~¼ inch (6 to 7.5 mm) long and usually green or sometimes purple spotted. Seeds are medium to dark olive brown or brownish-black with fine black spots, .8 to 1.4 mm long.

Notes:

Northern White Violet is a common species found in moist to wet woods, swamps, bogs, sedge meadows and peatlands. In Minnesota, this was previously known as Viola macloskeyi var. pallens (or sometimes V. pallens) but a major overhaul of Viola accounts published in 2023 has put V. macloskeyi in a western clade and reverted to the older name of V. minuscula for plants found throughout the rest of North America.

V. minuscula is recognized by: not more than about 8 inches tall (often half that); all basal leaves held ascending to spreading, blades up to 2¾ inches long, longer than wide or about as long as wide, egg-shaped to nearly round, shallowly toothed, green and hairless on both surfaces, leaf stalk hairless to sparsely hairy; white flowers mostly less than ½ inch long, lateral petals beardless or very sparsely bearded, beardless spur petal, short spur; leafy stolons produced in summer.

The two most similar species are Viola incognita (Sweet White Violet, formerly V. blanda) and Viola renifolia (Kidney-leaved Violet), both of which tend to have hairy leaves where V. minuscula is only sparsely hairy on the leaf stalk. V. incognita flowers are usually bearded, its seeds are medium to light brown and up to 2 mm long, and its stolons are very slender and usually naked except for a plantlet at the end. V. renifolia leaves are often wider than long, seeds are light to medium orange-brown to brown and no stolons are produced.