Common White Violet
Violet family (Violaceae)
Description: This native perennial plant produces a stem about ½1' long that often sprawls across the ground or leans against adjacent vegetation. This stem is light green and hairless. The blades of the alternate leaves are up to 2½" and 2" across; they are orbicular-cordate, medium green, mostly hairless, and crenate along the margins. While some young leaves are initially pubescent, they later become mostly hairless. The petioles of these leaves are rather stout and hairless; they are about as long as the blades of the leaves. At the base of each petiole, there is a large stipule up to 1" long that is lanceolate or narrowly ovate. These stipules are light green and hairless; there are linear to lanceolate teeth along their margins. Individual flowers develop from the upper axils of the leaves on slender pedicels; the pedicels of these flowers may be 4" long or longer. Each flower is about ¾" across; its corolla consists of 5 rounded white petals, while its calyx consists of 5 light green sepals. The two lower lateral petals have fine white hairs (or beards) near the throat of the corolla; the lowermost petal has purple lines that function as nectar guides. The spur of the corolla is rather short and blunt. The throat of the corolla isn't yellow. The blooming period occurs from mid-spring to early summer and lasts about 1½ months. There is no noticeable floral scent. If the flowers are cross-pollinated, they will produce tripartite seedpods. Later in the year, inconspicuous cleistogamous flowers are produced amid the foliage, and they are self-fertile. Mature seedpods can mechanically eject their seeds several inches. These seeds are small and brown. The root system produces rhizomes and fibrous secondary roots. This plant can spread vegetatively through its rhizomes.
Cultivation: The preference is light shade to partial sun, moist to mesic conditions, and a rich loamy soil. This species doesn't invade lawns because its stems are too long.
Range & Habitat: The Common White Violet is fairly common in the southern half of Illinois, but in the northern half of the state it is uncommon or absent (see Distribution Map). Habitats include moist to mesic deciduous woodlands, riverbanks in wooded areas, woodland borders, moist meadows, and ditches.
Faunal Associations: The flowers are pollinated by bees, particularly Osmia spp. (Mason Bees) and Andrena spp. (Andrenid Bees). One of these species, Andrena violae (Violet Andrenid Bee), is an oligolege of Viola spp. (Violets). Sometimes bee flies, butterflies, and skippers visit the flowers for nectar, but they are less effective at pollination. The caterpillars of Fritillary butterflies and several species of moths feed on Violets (see the Butterfly & Moth Table for a listing of these species). The seeds of upland gamebirds eat the seeds of Violets to a limited extent, including the Mourning Dove, Ruffed Grouse, Bobwhite, and Wild Turkey. The seeds are also eaten by the White-Footed Mouse, while the foliage is eaten to a limited extent by the Cottontail Rabbit.
Photographic Location: A wooded area of Meadowbrook Park in Urbana, Illinois.
Comments: This attractive violet should be cultivated more often it is not a difficult species. There are several Viola spp. (Violets) in Illinois that produce white flowers. The Common White Violet belongs to a group of violets that produce their leaves and flowers from stems other violets produce their flowers and leaves directly from their root system in the ground. The Common White Violet produces unusually large stipules at the base of its leaves (up to 1" long); the margins of these stipules have abundant fringe-like teeth (see the lower photograph). This latter characteristic separates this species from other white-flowered violets in Illinois. The species Viola canadensis (Canada Violet) produces white flowers from stems, but its stipules are quite small and they lack conspicuous teeth along the margins. A form of the Common Blue Violet, Viola pratincola alba, produces white flowers, but this is a stemless violet. Other common names for Viola striata are Cream Violet and Pale Violet.