Hyacinth bean

Hyacinth bean (Lablab purpureus), also called lablab, bonavist bean or Egyptian bean, is a twining herbaceous vine of the pea family (Fabaceae), genus Lablab, usually annual (sometimes short-lived perennial), growing 1–6 m long. The stems branch, bear fine hairs and are green or purple-tinged. The leaves are trifoliate; the leaflets are broadly ovate-rhombic, 5–15 cm long, entire and softly hairy, and some cultivars are suffused with purple. The inflorescence is an erect axillary raceme bearing 20–40 papilionaceous (pea-like) flowers in purple, violet-pink or white, with a prominent standard petal; flowering occurs in summer–autumn. The fruit is a curved, broad, flattened legume (pod) 4–6 cm long and 1.5–2.5 cm wide, containing 3–5 seeds; pods are green or deep purple when young and dry brown at maturity. The seeds are kidney-shaped, 8–12 mm long, white, brown, black or mottled, with a conspicuous white hilum — the edible lablab bean.

Updated by lebachungtdh@gmail.com · 10/12/2026

Hyacinth bean is native to tropical Africa (East and southern Africa) and possibly South Asia, with India as a secondary centre of diversity; it is now cultivated throughout Africa, South Asia, Southeast Asia, China, the Americas and the Caribbean. It prefers a warm, sunny climate and tolerates drought fairly well, climbing over trellises, fences and field margins. The seeds are rich in protein (20–25%), starch and fibre and are eaten as a pulse (in dhal, curries and soups); young pods and young leaves are also cooked as vegetables. The purple pod walls contain antioxidant anthocyanins. The seeds and leaves contain cyanogenic glycosides (linamarin) and trypsin inhibitors, so they must be thoroughly cooked before eating. In Chinese medicine the seed (扁豆) is sweet and neutral (sometimes warm): it strengthens the spleen, dries dampness and clears summer-heat, and is used for diarrhoea, vomiting, poor appetite, abdominal fullness and sunstroke; roasted seeds are considered more tonifying for the spleen. The plant also serves as fodder, green manure, a cover crop and an ornamental (purple-flowered cultivars). It has not been assessed by the IUCN and is therefore listed as Not Evaluated (NE).

Updated by lebachungtdh@gmail.com · 10/12/2026