This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Glabrous, cespitose, the stout ascending rootstock often branching; leaves at vernal flowering 3'-6' high, the blades ovate-deltoid, cordate at base, often with concave upper margins; mature leaves 6'-12' high, the blades 2 1/2'-4' wide, as long as broad, acuminate, rather coarsely crenate-serrate; corolla pale violet with a darker band above the white center, spurred petal glabrous; sepals lanceolate or ovate-oblong and obtuse, narrowly white-margined, slightly ciliolate; capsules from apetalous flowers broadly ellipsoid, finely dotted with brown, 5"-6" long; seeds bright buff, nearly 1" long.
Viola cuspidata Greene, Pittonia 3: 314. 1898.
Rootstock stout, often branching; petioles and under surface of young leaves, and often the scapes, villous-pubescent; the blades ovate to orbicular or even reniform, with an obtuse short point, cordate, crenate-serrate, sometimes 4' wide when mature; corolla violet to lavender, and occasionally white; outer sepals ovate-oblong, commonly obtuse, all finely ciliate below the middle and on the short rounded auricles; cleistogamous flowers ovoid on short horizontal peduncles, usually underground, but lengthened and erect when the capsules ripen; capsules usually mottled with brown; seeds dark brown, 1" long.
Plants of small size; rootstock short, thick; leaves frequently appressed to the ground, the blades orbicular to reniform, cordate, obtuse, \'-2' wide, purplish and glabrous beneath, silvery pubescent above; often purple-veined and mottled with different shades of green; flowers reddish purple on peduncles exceeding the leaves, lateral petals bearded, spur about 2" long, very blunt; apetalous flowers small, ovoid, on short prostrate peduncles, their capsules ovoid, 3" - 4" long, purplish, bearing each 20-30 light brown seeds.
Copses in dry rich soil, southern New York to central Alabama and Georgia. Hairy violet. April-May.
Viola septentrionalis Greene, Pittonia 3: 334. 1898.
Rootstock at length stout and branching; scapes and leaves at vernal flowering 3'-5' high, more or less hir-sutulous except the earliest leaves; blades ovate to reniform, cordate, ciliate, somewhat pointed but the apex blunt, becoming 2'-3' wide when mature; petioles slender, wiry, often purplish at base; petals variable, 4"-6' wide, deep violet to pale lilac, rarely pure white or white suffused with violet, the three lowest villous at the base, all occasionally bearing scattered hairs; sepals ovate, usually obtuse, closely ciliolate nearly to the tip; cleistogamous flowers sagittate, on ascending peduncles; their mature capsules purple or sometimes green, subglobose, 2 1/2"-4" long, subtended by the spreading ciliolate auricles of the sepals; seeds dark brown.