A low, shrublike perennial with twisting stems that are erect, reclining, or vining, with soft, short hairs. Flowers solitary or few on very short peduncles, to 2 inches long, beautiful pale blue and lilac with darker veining, arising from leaf axils. The overall floral structure is that of typical pea flowers, though the standard (the large upper petal) is comparatively much larger than usual. One scientist has suggested that late in the season the plant produces small, budlike, insignificant flowers, which also produce seed. Blooms May–September. Leaves alternate, compound, with 3 leaflets, the center leaflet on a longer stem than the two lateral ones. Fruit a bean pod about 2 inches long.
Stem length: to 3 feet.
Where To Find
Occurs in acid soils in open upland or lowland woods, borders of glades, ravines, and stream openings.
Early botanists named this plant's genus for its resemblance to the human female genitalia. The genus occurs worldwide in temperate and tropical areas, and the different species often have common names that mean about the same thing, in the various local languages.
Insects, including leaf miners and some butterfly and moth larvae, eat the leaves. Although it is called "butterfly pea," bees, not butterflies, seem to be the primary pollinators. The common name apparently came from the flower's resemblance to a butterfly's spread wings.
About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!