Centrosema virginianum and Clitoria mariana are North American native perennial herbaceous leguminous vines with potential for the wildlife garden.
When plants have the same common name, they are often very dissimilar. Such is not the case with two butterfly peas, Centrosema virginianum, the spurred or climbing butterfly pea and its close cousin, Clitoria mariana, the Atlantic pigeonwings.
The shape of the flower looks like a butterfly, hence botanists describe the five-petaled flower form as papilionaceous from the Latin word papilio meaning butterfly.
Both butterfly pea flowers have a large posterior platform petal topped with two small lateral petals called wings and two smaller petals called keels at the center. Centrosema’s circular floral platform, violet to violet-pink, expires in a day. Clitoria’s oblong flower, light blue to pale pinkish purple, persists for several days.
Both wildflower vines bloom throughout summer. The large posterior platform petal serves as a landing site for pollinators that follow colored markings of white, purple or yellow to guide them to the nectar beneath the central keels. Bees, flies and butterflies maneuver to the interior of the flower.
One result of pollinator labor is seed. Following flowers fruit known as pods form. Centrosema grows slender flat pods 3-6 inches long. Pods twist open when dry releasing 10-20 seeds per pod from July through November.
Clitoria has flat smooth pods which are 1-2 inches long and contain 2-6 black seeds. As pods dry, they twist open revealing sticky adhesive seed.
Centrosema and Clitoria have alternate compound dark green leaves with three leaflets. The underside of Centrosema is light green and the underside of Clitoria is coarsely veined.
Golden-banded skippers lay strings of 2-7 eggs on the underside and base of Clitoria leaflets. Their green-bodied caterpillars with reddish-brown heads live in rolled up leaves and emerge at night to feed on leaves.
Butterfly gardeners might consider growing this vine just for the colorful caterpillars.
Home gardeners may find these vines growing naturally in wild areas of their property. They like sunny or partially sunny locations.
These native plants have adapted to acid soils, dry soils, woodlands, and pinewoods of the eastern and southeastern United States. If these plants are native to your area, they may not require a great deal of soil preparation.
Both vines are modest and delicate rather than bold and invasive in growth habit. Centrosema spreads and twines 6-12 feet. Clitoria spreads 3-4 feet.
A lacy latticework or screen would make a man-made support. These vines will use neighboring vegetation to climb without harm to them.
Propagation of Butterfly Pea
Butterfly pea is grown from seed. Native seed suppliers like Roundstone and native plant nurseries carry the plants.
Nitrogen Fix with Butterfly Pea
Nitrogen is an essential element for all plants. Legumes like butterfly peas are capable of adding nitrogen to the soil for plants through a symbiotic relationship between Rhizobia bacteria living in nodules of the roots. The bacteria convert atmospheric nitrogen to nitrate in the soil for the plant to use.
Gardeners who grow native legumes do not rely on chemical fertilizers to supply nitrogen.
Uses for Wildlife
Besides attracting pollinators to the garden, songbirds and bobwhite come for the seeds. Birds help disperse the seed to new locations.
White-tailed deer consider the vine good browse.
Two of a kind butterfly peas like Centrosema virginianum and Clitoria mariana are easy-to-grow enduring representatives for the native wildlife garden.