Phaseolus Polyanthus Beans

Phaseolus Genus

• Phaseolus is a genus of legumes that contains 55 species, but only five of those species, the plants commonly called beans, have been domesticated and cultivated as a food source. The plants' seeds historically have been an important source of protein in some cultures, especially in Mesoamerica. Beans are grown most often as annuals, but some species, including the cache bean, can be perennial in U.S. Department of Agriculture hardiness zones 10 and above.

Cache Bean

• The cache bean is related closely to the scarlet runner bean (Phaseolus coccineus), but it can be distinguished by its germination habit, in which the seedling's seed leaves emerge from the ground, as opposed to the runner bean's germination, in which the seed leaves remain below ground. The cache bean plant produces white or pale purple flowers on spike-shaped flower stalks containing 6 to 16 flowers each. The flowers develop into seed pods, and each pod contains several seeds that usually ripen to an orange or yellow color, although some individual plants may produce brown, black or white seeds.

Habitat and Cultivation

• Cache bean is cultivated in Mesoamerica and South America, where it's grown in cool, humid climates at elevations between 2,600 and 8,500 feet. It prefers organically rich, damp, well-drained soil, and it is tolerant of partial shade. In humid climates, it's perennial, with a lifespan of 2 to 4 years, but in drier climates it can be grown as an annual. It flowers continuously over a period of 2 to 5 months, and in wet climates it may have two flowering periods per year.

Uses

• Cache bean often is grown together with other species of bean, including tepary bean (Phaseolus acutifolius), kidney bean (Phaseolus vulgaris) and scarlet runner bean. These other species typically are dried before they're eaten, but the cache bean is eaten traditionally green, after the seed has reached full size but before it matures completely. It is used in soups and stews, and in some parts of South America it is eaten as a sweet treat.