YAMS. 



By W. Harris, F.L.S., Superintendent of Hope Gardens. 



As far as I am able to gather the cultivated yams of Jamaica 

 may all be referred to four species of Dioscorea, viz. : — 



D. sativa, Linn.. D. alata, Linn., D. cayennensis, Lam., and D. 

 trifida, Linn., all climbing plants belonging to the order Dios- 

 coreaccea, and cultivated in the tropics. 



It is exceedingly difficult to get good botanical specimens of 

 these cultivated plants, but from enquiries made amongst cultiva- 

 tors, and by carefully comparing the information thus gained with 

 the published descriptions of cultivated species of Dioscorea, I have 

 arrived at the determinations here given. If ever the numerous 

 recognised varieties are critically examined, it is possible that 

 some of those now included D. sativa, and D. alata will be referred 

 to other species. 



Dioscorea sativa, Linn. " Negro Yam. " 



Stem cylindrical, not winged, more or less prickly ; leaves heart- 

 shaped, roundish, gradually tapering into a sharp point. 



Tuber large, of a dark colour externally, but the end white and 

 bitter when boiled if not perfectly ripe. This yam is of a dirty 

 white colour when cooked, and is soft, but is considered a good 

 yam. 



The Negro Yam is always cut before it is quite ripe, otherwise 

 a very small " head" for planting would be obtained. It is a hardy 

 yam and is the best kind for cold districts in the hills. 



Varieties. — " Man Yam." A larger yam and better flavoured than 

 the " Negro." Tuber oblong, of nearly the same diameter through- 

 out its length. This is allowed to ripen before being cut. 



" Litcea Yam." This is a longer yam than either the " Negro" 

 or the " Man." In flavour it is considered superior to the " Negro" 

 but inferior to the " Man." Tuber about the same thickness 

 throughout its length. This yam is largely cultivated in the 

 western parishes (Hanover, &c.), and is shipped in considerable 

 quantities from the port of Lucea (hence its name) to Kingston, 

 also to Cuba. It is a first-rate yam. 



" Mozclla," or " Bitter Yam." Very like the "Lucea," but of a 

 purplish colour underneath the skin, and with a bitter taste when 

 cooked, even when carefully cured. 



The stems of this variety climb to a great height, reaching the 

 top of the highest tree if they happen to get hold of the branches. 



Dioscorea alata, Linn. "White Yam." 



India. Stems sharply angled, winged ; leaves heart-shaped, 

 roundish, or pointed, variable in size and shape, often very large. 

 Tuber very large as a rule, white. 



Varieties: — "Guinea Yam." One of the larges white yams. 

 Skin smooth ; tuber soft when cooked, flavour good. Like the 

 " Mozella Yam," the stems climb to a great height. 



