Clitoria ternatea aka Butterfly Pea

Clitoria ternatea, or butterfly pea, belongs to the bean family. It is a short-lived vine from the tropics. Kew places its native range in Cape Verde and Africa. That range also includes the Arabian Peninsula. Other sources note doubt about its exact place of origin. It now grows wild across much of the tropics. It occurs in grassland, open woods, and disturbed ground.

Thin stems climb, scramble, or trail from a woody base. Garden plants reach about 10 feet [3 metres] tall. Some reach 15 feet [4.57 metres] with support. Their spread can reach 6 feet [1.83 metres]. Growth is fast, and the smooth stems lack scent. Sources differ on whether plants keep or shed their leaves. The green leaves grow in an alternate pattern. Each pinnate leaf has five to nine oval leaflets. Their edges are smooth, with no teeth.

Blue to violet flowers have pale or yellow centres. Each pea-like bloom measures about 0.17 feet [0.05 metres] across. The broad upper petal has a notch at its tip. Flowers grow from leaf joints, alone or in small groups. The main bloom season runs from summer into fall. Insects pollinate the flowers, and the plant attracts butterflies. Birds and moths also visit it. Flat pods follow the flowers and turn brown as they mature.

Grow butterfly pea in full sun and fertile, well-drained soil. Light afternoon shade suits it in hot places. It tolerates sand, loam, clay, and a broad pH range. It withstands dry spells but grows best with steady moisture. Sources place its hardiness within USDA zones 10–12. In cooler regions, gardeners grow it as an annual. A greenhouse can shelter it where outdoor temperatures are too low. Seeds offer an easy way to start new plants. Give the vine a trellis, arbor, or hedge to climb. Its trailing growth also serves as ground cover. Dense growth helps protect soil from erosion.

Spider mites and whiteflies can attack the plant. Anthracnose and bacterial soft rot can also cause harm. Flowers supply blue colour for foods and drinks. Acid turns this colour pink. People eat young pods and cook young leaves as vegetables. Leaves and flowers also yield dye for other uses. Useful Tropical Plants records medicinal uses and reports no known hazards. This does not establish safety for every part or use.