Yellow Yam, Yellow Guinea yam

Dioscorea cayennensis

Physical Characteristics

Dioscorea cayennensis is an evergreen Perennial Climber growing to 10 m (32ft) by 0.5 m (1ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. The flowers are pollinated by Wind, Insects. The plant is not self-fertile. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid and very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Western Africa - possibly Dahomey.

Habitats

Edible Uses

Edible Parts: Leaves Root Edible Uses: Tea Root - cooked in various ways and eaten as a vegetable[ 300 , 301 ]. A palatable flavour with a dry, mealy flesh[ 301 ]. The roots are sometimes dried and milled to produce a flour for storing - this flour is then stirred into boiling water and kneaded to form a paste[ 299 ]. The roots have a rough outer skin and a pale yellow flesh[ 301 ].The roots are up to 3kg in weight[ 300 ]. The roots can contain up to 91% carbohydrate, the highest for any yam[ 332 ]. Protein content is low, about 2.5%[ 332 ]. A tea is made from the leaves[ 301 ].

Medicinal Uses

None known

Known Hazards

Freshly cut tubers can cause skin irritation due to the presence of raphides, which are destroyed when the tubers are cooked[ 299 ].