Traditional Green Vegetables: The Plants

Arrowroot (Colocasia esculenta), nduma (Kiswahili).  A perennial herb belonging to the family Araceae about 1 m in height with a whorl of arrowhead-shaped leaves born on long petioles emerging from an underground, starchy corm.  This crop is also known as coco yam (West Africa) or taro (Polynesia), originated in South East Asia and spread to the Mediterranean and Egypt before 100 A.D., and then to East, Central and West Africa.  Plants are propagated from the cut tops when roots are harvested or from vegetative plantlets (suckers).  This crop prefers moist soil and is often grown in valley bottoms and poorly drained areas at a spacing of 50 to 90 cm. Roots require 6 to 10 months growth before harvest but the younger leaves may be collected as needed.  The leaves, petioles and corms (roots) are edible but require lengthy boiling as the entire plant contains crystals of calcium oxalate, a severe irritant.  The leaf veins and petiole “skin” are particularly high in calcium oxalate and must be cut away or peeled prior to cooking.  The cooked leaves contain 3% protein, 6% carbohydrate and are rich in Vitamin C.  Arrowroot is sometimes confused with Xanthosoma sp., which is also called cocoyam in West Africa, but does not have edible leaves.