Violet family (Violaceae)
Description: This perennial plant is about 3-6" tall. It consists of a rosette of basal leaves, from which one or more flowering stems may emerge that are somewhat taller. The basal leaves have a deeply lobed palmate structure, and are rather fan-shaped in appearance. They are up to 1" across and have petioles up to 1" long. The flowering stems are more or less erect, but curve abruptly downward where the flowers or buds occur. These flowers are about ¾" across and quite similar in appearance to other violets. They have 5 petals that are blue-violet or pale blue-violet, and 5 green sepals that are long and pointed, but remain behind the petals. The two upper petals are more or less rounded, but sometimes they are rather elongated. The lower side petals have white hairy beards at the throat of the flower. At the base of the lower center petal is a patch of white with fine lines of purple that function as nectar guides to visiting insects. The Prairie Violet usually blooms from mid- to late-spring, but it can also bloom during the fall under favorable conditions. There is no noticeable floral scent. During the summer months, inconspicuous cleistogamous flowers mature into seedheads that are brown and triangular-shaped. These release little brown seeds by mechanical ejection, which can fall to the ground several inches away from the mother plant. The root system is fibrous, and can form rhizomes.
Cultivation: The preference is full sun and mesic conditions. Some shade from grasses and other plants later in the year is normal and tolerated. The soil should have the capacity to retain some moisture during summer dry spells, preferrably with high organic content. This plant can be difficult and short-lived if a site doesn't satisfy its requirements.
Range & Habitat: The native Prairie Violet is an uncommon plant in the northern half of Illinois, and rare or absent in the southern half (see Distribution Map). Habitats include mesic to slightly dry black soil prairies, savannas, and loess hill prairies. It is not normally encountered in disturbed or developed areas, but can be considered an indicator plant of high quality prairie remnants. Occasional wildfires are probably a beneficial management tool, as this removes much of the brush and dead debris that can smother these little plants.
Faunal Associations: Little information about flower-visiting insects is available for this species of violet, but similar violets attract Anthophorine bees, Mason bees, Eucerine Miner bees (Synhalonia spp.), Halictine bees, small butterflies, and Duskywing skippers (Erynnis spp.). Syrphid flies also visit violets, but they feed on stray pollen and are non-pollinating. Because these insect visitors are uncommon during the spring, the Prairie Violet is capable of self-fertilization, like many other violets. The caterpillars of various Fritillary butterflies feed on this and other violets, including Euptoicta claudia (Variegated Fritillary), Speyeria cybele (Great Spangled Fritillary), Speyeria aphrodite (Aphrodite Fritillary), Speyeria idalia (Regal Fritillary), Speyeria diane (Diana), and Boloria selene myrina (Silver-Border Fritillary). The small size and early growth habit of this plant provide some protection from mammalian herbiovres.
Photographic Location: One photograph was taken at Loda Cemetery Prairie in Iroquois County, Illinois, while the other photograph was taken by Lisa Culp (Copyright © 2010) at a nature preserve in Cook County, Illinois. In one of the photographs, the small deeply lobed leaves of the Prairie Violet are located toward the bottom in the center, peeking out from dead leaves of grasses; the larger leaves behind and directly underneath the flower are from unrelated species of plants.
Comments: The deeply lobed leaves of Prairie Violet are similar in appearance to those of Viola pedata (Bird Foot's Violet), but the latter doesn't have tufts of white hair at the throat of its flowers. Also, the flowers of Bird's Foot Violet are slightly larger in size and sometimes fragrant.