Fourteen are plants without leafy stems. The leaves and flowers come separately from the ground, or from runners on the ground.
Viola rotundifolia, Yellow Roundleaf Violet Rare native, Piedmont only
This is the only yellow violet in Delaware without leafy stems.
Viola blanda, Sweet White Violet Uncommon native, Piedmont only
Leaves heart-shaped, petals beardless, upper petals twisted.
Viola macloskeyi var. pallens, Smooth White Violet Rare native, Piedmont & coastal plain
Leaves heart-shaped, side petals bearded.
Viola primulifolia, White Primrose-leaved Violet Native, Piedmont & coastal plain
Leaves broader at the base than the tip, but not heart-shaped.
Viola lanceolata var. lanceolata, White Lance-leaf Violet Native, Piedmont & coastal plain
Leaves long and narrow, tapering at both ends.
Viola pedata, Blue Bird's-foot Violet Rare native, Piedmont & coastal plain
Leaves divided into narrow segments, flowers with prominent orange stamens.
Viola brittoniana var. brittoniana, Blue Coast Violet Uncommon native, coastal plain only
Leaves divided into narrow segments, flowers without prominent orange stamens.
Viola palmata, Blue Palmate-leaved Violet Uncommon native, Piedmont & coastal plain
Leaves divided into wider segments; may also have some undivided leaves.
Viola cucullata, Blue Marsh Violet Native, Piedmont & coastal plain
Hairless, found in wet places, flowers usually darker in the center.
Viola sagittata, Blue Arrowleaf Violet Native, Piedmont & coastal plain
Leaves arrow-shaped, triangular, with a few hairs.
Viola fimbriatula, Blue Fringed Violet Native, Piedmont & coastal plain
Leaves arrow-shaped, hairy on both sides.
Viola hirsutula, Southern Blue Wood Violet Native, Piedmont only
Flowers reddish-purple; leaves "silvery-hairy and somewhat mottled above, often with purple veins."
Viola odorata, Sweet Violet Non-native, Piedmont only
Flowers scented; style hooked; spreading by runners.
Viola sororia, Common Blue Violet Native, Piedmont & coastal plain
May be hairy or hairless (formerly considered separate species.) I would probably call any stemless blue/purple violet in Delaware Viola sororia if it wasn't clearly one of the five above. The pale form is the "confederate violet."
Seven are plants with leaves and flowers on upright stems:
Viola pubescens var. pubescens, Downy Yellow Violet Native, Piedmont & coastal plain
The whole plant is covered with short hairs.
Rare on the coastal plain.
Viola pubescens var. scabriuscula, Smooth Yellow Violet Native, Piedmont & coastal plain
May have a few hairs, but basically smooth.
Rare on the coastal plain.
Viola striata, Striped White Violet Uncommon native, Piedmont only
This is the only white violet in Delaware with leafy stems.
Viola arvensis, Small Wild Pansy Non-native, Piedmont & coastal plain
Petals are white and yellow, sometimes with purple tips.
Viola labradorica, Blue American Dog Violet Uncommon native, Piedmont only
Pale with darker veins, and a long spur. Sure looks like a dog's head to me.
Viola tricolor, Three-colored Violet Non-native, Piedmont & coastal plain
Upper petals purple, lower yellow and white. (Johhny Jump-up)
Viola bicolor, Field Pansy Native, Piedmont & coastal plain
Petals pale blue, often marked with yellow. Large, lobed, stipules.