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..
V. triloba Schwein. Am. Journ. Sci. 5: 57. 1822.
V. congener Le Conte, Ann. Lye. N. Y. 2: 140. 1826.
Earliest leaves and those put forth in late summer usually with uncut blades, reniform, cordate, sparingly pubescent or glabrate; those unfolding at petaliferous flowering densely villous beneath and on the petioles, the blades 4'-6' wide when mature, 3-lobed or rarely 3-parted, the middle segment broad, the lateral lunate, divaricate, often coarsely toothed or cleft; peduncles mostly glabrous, shorter than the leaves; petals deep violet; outer sepals ovate-lanceolate, somewhat obtuse, slightly ciliate, cleistogamous capsules ovoid, purplish; seeds buff or brown.
Dry woodlands, southern New England and New York, south to Georgia and Alabama. Var. dilatāta (Ell.) Brainerd (V. falcata Greene), in which the pedately cut leaves have more numerous and deeper incisions, occurs from Missouri eastward to the coast and southward to Louisiana and Florida. April-May.
Viola domestica Bicknell, 111. Fl. 3: 519. 1898.
Viola pratincola Greene, Pittonia 4: 64. 1899.
Plants usually glabrous, robust from a stout branching rootstock; petioles sometimes sparingly pubescent, becoming much longer than the blades; these often 5' broad. reniform or ovate, cordate, acute or sometimes abruptly pointed; scapes shorter than the leaves; corolla deep violet, white or greenish yellow at the center, sometimes wholly white; the odd petal often narrow and boat-shaped, usually beardless; outer sepals ovate-lanceolate; capsules ellipsoid, green or dark purple, 5"-7" long; seeds 1" long, dark brown.
Moist fields and groves, frequently about dwellings, Massachusetts to Minnesota, south to Georgia and Oklahoma. Ascends to 6000 ft. in Virginia. Long-stemmed purple violet. Fighting cocks. Common blue violet. April-May.
Figured as V. obliqua in our first edition.
Viola latiuscula Greene, Pittonia 5: 93. 1902.
Glabrous except for more or less puberulence or granular roughness on the edges of the petiole near the blade; when in petaliferous flower 2 1/2'-5' high, the blades broadly ovate-deltoid, cordate, about 1' wide, the earliest obtuse and tinged beneath with purple; mature leaves often 8'-12' high, the blades 1 1/2'-4' wide, sometimes much dilated and abruptly pointed; flowers large, deep violet, the spurred petal villous at base; outer sepals lanceolate, glabrous, with short rounded auricles; cleistogamous flowers on short, horizontal peduncles, their capsules ellipsoid, flecked with purple, 4"-6" long, the persistent sepals one-third as long; seeds brown.