Phaseolus lunatus L.

Erect, ascending or nearly prostrate slender vine, sometimes somewhat scan-dent, sometimes branched; stems pilose with weak hairs, glabrescent. Leaves pinnate trifoliolate, leaflets ovate to deltoidal, sometimes rhombic ovate, apically deltoid, blunt but mucronulate, basally broader, sometimes rounded, mostly 6-8 cm long, 4-6 cm wide, 3 veined from the base, the lateral veins distally arcuate, somewhat evanescent, mostly drying concolorous, the sparse minute pubescence mostly confined to the costa; petiolules 2-3 mm long, puberulent; rachis mostly 1.5-3 cm long; stipels minute but evident, persistent, mostly 0.5-1.0 mm long; petioles mostly longer than the terminal leaflet, glabrate or sparingly pubescent with weak, subappressed hairs at anthesis. Inflorescences axillary or lateral, short or elongate pseudoracemes to 25 cm long, the nodes often well spaced proximally, more condensed distally, the bracts mostly 2-3 cm long, acute, sericeous, incon-spicuous, the rachis and the peduncle sparingly pilose, glabrescent; pedicels 1-4 per node, slender, 6-9 mm long; bracteoles mostly ca. 1 mm long, pubescent or not, 3-nervate, spathaceous, subtending the calyx less than 1/2 as long as the calyx. Flowers greenish or purplish, the calyx 2-3 mm long, the tube campanu-late, the limb somewhat flaring, the lobes rounded or short deltoid, ciliolate; standard ca. 1 cm long, broad, flat, often puberulent externally, keel spiralled. Legume flat, slightly turgid around the seeds, falcate, 3-8 cm long, 1.5-2 cm broad, glabrate; seeds 2-4, reniform, compressed.

It suits warm and subtropical areas. In the tropics it is common between 500 and 2100 m altitude but grows to the limit of cultivation (2700 m). For germination it must have a soil temperature above 15.5°C and cannot withstand frost. In very hot weather seeds often do not set. It does best in a temperature range 14-21°C. It is sensitive to a pH less than 6. It can grow in arid places. It suits hardiness zones 8-11. In Yunnan.

The leaves, young pods and seeds are all eaten. The seeds are eaten fresh or after drying. They are also fried in oil. Dried beans are boiled or baked. They can be used in soups and stews. The seeds are sometimes grown as bean sprouts then cooked and eaten. CAUTION Some kinds have poison (hydrocyanic acid). This is destroyed by thorough cooking. As well the beans contain a protein inhibitor but this is destroyed by cooking.

It is grown from seed. Coloured seeds are often hard to get to grow but white seeded kinds start growing easily. Sow 3-4 seeds in a hill and put a stick 2-3 m tall in the middle. Hills should be about 1 m apart. Seeds should be 2-4 cm deep.