Dioscorea trifida aka Indian Yam

Dioscorea trifida is a climbing yam in the Dioscoreaceae family. Its common names include cush-cush, yampee, and yampi yam. It comes from tropical America. Its range spans northern South America, Central America, and the eastern Caribbean. Growers raise it for food across the tropics, including South America and the Caribbean. It is a perennial with a tuberous rootstock.

The twining stems reach about 10 feet [3 metres] long. They trail across the ground or climb through nearby plants. Plants grow fast and reach about 1.6 feet [0.5 metres] wide. PFAF describes the plant as evergreen. Small green flowers grow in the leaf axils. Each flower has six tiny tepals. The fruit is a winged capsule with fine hairs. Wind and insects pollinate the flowers.

This yam suits warm, moist tropical and subtropical sites. It grows best with daytime temperatures of 18–26°C. Temperatures of 7°C or below can kill it. PFAF lists it for USDA zones 10–12. Give it sun, though it can cope with some shade. It needs moist soil that drains well and holds organic matter. It can grow in sandy, loamy, or clay soils. Its preferred pH is 6–6.7, though it tolerates 5.3–8. Long days early in the season help the stems grow. Shorter days later help the tubers form and swell.

The tubers are the main reason to grow this plant. Plants form groups of 5–50 tubers on swollen runners. A crop takes about nine to eleven months from planting. Tubers measure roughly 0.5–0.7 feet [0.15–0.20 metres] long. They are about 0.2–0.3 feet [0.06–0.08 metres] thick. Cook them by boiling or baking. The cooked flesh has a smooth, moist texture and rich taste. Its waxy starch may also serve as a food thickener or binder.

Growers can raise plants from seed or pieces of tuber. Sow seeds in containers before planting out as growth starts. Each tuber piece needs two or three dormant buds. Cut pieces can dry in the sun for several hours. This helps wounds heal and lowers the risk of fungal infection. PFAF and Useful Tropical Plants list no known hazards. That does not establish the safety of every plant part. PFAF records no known medicinal use.