VEGETABLES A\ 7 D FOOD PRODUCTS 221 



even preferred to good potatoes. In Ceylon and the Eastern 

 Tropics, however, they have not as yet gained such popularity, 

 either with the Natives or Europeans, and though often met with in 

 native gardens, as well as in markets and boutiques, they are not 

 a common commodity. Yams are easily cultivated, and thrive best 

 in loose deep soil, up to an elevation of 2,500 to 3,000 ft. They 

 may be planted against fences, trees, etc., or made to serve as 

 screens for covering unsightly objects. The best season for 

 planting is February and March. The ground being dug to a 

 depth of 1 i to 2 feet and raised in drills or mounds, 4 feet apart, 

 pieces of the crown or "yam head" are planted in these at distan- 

 ces of 2 feet apart. Poles or stout bamboo tops are fixed in the 

 ground along the rows for support to the vines. The crop is ready 

 for harvesting in from 7 to 9 months, the leaves then becoming 

 spotted brown, and the stems dying down to the ground. The 

 tubers may be lifted and stored in a cool shed, under dry earth or 

 sand; or they may be left in the ground and used as required, pro- 

 vided they can be protected from vermin and other enemies. Yams 

 can be cooked and prepared for food in various ways, being either 

 roasted, baked, or boiled and steamed, etc. 



VARIETIES. There are numerous species and varieties of yams, some 

 half-dozen species being indigenous to the moist low-country jungle of 

 Ceylon. Most of the cultivated forms are somewhat variable in their 

 vegetative characters, colour and shape of tuber, and a great number 

 of these probably belong to the species D. alata. The local vernacular 

 names are numerous and confusing ; those here given include the 

 principal names known in Ceylon. Among the choicest varieties 

 are : Kiri-kondol, Hingurala, Japana-ala, Java-ala, and Kukul-ala. 

 Yampee or Cush-cush is a favourite yam in the West Indies. 



The following yams are grown in the Royal Botanic Gardens, Peradeniya : 

 Stem 3 to 5 winged or angled, tuberiferous, without prickles; leaves 

 opposite, entire. Dioscorea alata, var : 



"Angili-ala" S. (= "Verralvalli-kelengu" J), "Bindhar" or "Binnar- 

 ala" S, "Hingur" or "Ingur-ala" S, "Japana" or " Rathu-ala" S. 

 (="Sayuyalli-kelengu"70. "Kaharata-ala" S (== Karavalli-kelengu" T.), 

 "Kiri-kondol" S (= "Arthuvalli-kelengu" T) or White yam, "Kirivel- 

 ala" S (= " Vaithilay-valli-kelengu" T), "Xiame-Chino" and "Niame 

 Pellu" (Cuban names), "Raja-ala" S, " Rata-kondol" S, "Ratavel- 

 ala" S, "Vel-ala" S (= "Kodivalli-kelengu" T), and Yellow-yam 

 (= D. Caycnnemis). 



Leaves 3 to 5 lobed, stem winged: Yampee or Cush-cush yam (=D. trifida]. 



Stem round, tuberiferous, without prickles, leaves alternate : "Udella" 

 or "Uda-ala" S (= " Kodikarrana-kelengu " T)= D. bnlbifera. 



Stem round or slightly grooved, tuberiferous, with prickles, leaves alternate 



