African Yam Bean

African Yam Bean

Latin Name: Sphenostylis stenocarpa

USDA Hardiness: 10-12

Native Range: AFRICA: Ethiopia, Chad, Kenya, Tanzania, Uganda, Burundi, Central African Republic, Democratic Republic of the Congo, Côte D Ivoire, Ghana, Guinea, Mali, Niger, Nigeria, Togo, Angola, Malawi, Zambia, Zimbabwe.

Edibility Rating: 4 / 5

Medicinal Rating: 0 / 5

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Plant Type:


Medicinal Uses

Edible Uses

Edible Parts: Leaves  Root  Seed  Seedpod | Edible Uses: Immature seedpods - cooked and used as a vegetable[300 ]. The pods are up to 25cm long and 15mm wide[300 ]. Seeds - cooked[300 ]. Rich in protein, they are boiled and eaten as a vegetable, or added to soups etc[301 ]. The seed is about 9mm long[300 ]. Root - raw or cooked[300 ]. The white fleshed roots can be cooked like potatoes, which they resemble in taste[301 ]. They are rich in protein[301 ]. Leaves - cooked and used as a vegetable[300 ].

Cultivation

Agroforestry Services: Nitrogen  Management: Standard  Regional Crop  Staple Crop: ProteinA plant of the tropics, where it is found at elevations up to 2,000 metres. It grows best in areas where annual daytime temperatures are within the range 23 - 29°c, but can tolerate 15 - 35°c[418 ]. It prefers a mean annual rainfall in the range 1,000 - 1,200mm, but tolerates 800 - 1,400mm[418 ]. Requires a dry period when flowering[300 ]. Prefers a position in full sun[418 ]. Grows best in a fertile, sandy soil[300 ]. Prefers a pH in the range 5.5 - 6, tolerating 4.5 - 7[418 ]. Although perennial, the plant is usually treated as an annual in cultivation[418 ]. Harvesting of the seedpods can commence about 5 months after sowing, and continue for another 2 months[300 ]. Tubers mature 7 - 8 months after sowing[300 ]. Optimum yields of the seed is 2 tonnes per hectare, and of the tubers 4 tonnes[418 ]. Plants are probably day length sensitive[300 ]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[200 ]. When removing plant remains at the end of the growing season, it is best to only remove the aerial parts of the plant, leaving the roots in the ground to decay and release their nitrogen.

Known Hazards

None known

Habitats

Brachystegia woodland, riparian and lakeshore bushland, grassland, roadsides, often in rocky places and on termite mounds, at elevations of 10 - 1,500, occasionally 2,000 metres[308 ].