SOS II OUT US JAMAICENSIS. yams 



YAMS. DlOSCOREA. 



Cl. 22, on. G Ih'acia hcxa-vdria. !\ \t. OK.S'armen!ace,?. 

 So tinmen in honour of Pedicious Dioscorides, supposed to have lived in the time of 

 Nero, and author of a Treatise on the Materia Medica. 



Gf.V. chXr M !e calys a one-leafed hell-formed perianth, six-parted; division! 

 1 inceolate, srireading at top : no corolla, unless the ralyx ; stamens six capillary fi- 

 laments, very sbort,Nvith simple anthers : Female calyx a perianth as in the male; 

 t6 corolla 5 the pistil has a very small three-sided germ, three simple styles, and 

 Simple stigmas ; the pericarp.is a large triangular capsttle, three-celled, three- 

 Viilvcd : Seeds in pais.-., compressed, girt with a large membranous border. 



I. SAT'.VA. cultivated. 

 FthibiUs nigra, radiee tuberosa compressa maxima digitata Jarinacea 

 csculrntajolio cor da to neivoso. Sloane, v. 1, p 14o. 



T.cr.res cordate ; alternate; ste^n even, round. 



This is commonly called negro yam, which has a round, smooth, slender, climbing, 

 Btem, rising to the. height of fifteen or twentj feet, when supported, the lower part of 

 the .stem somevi hat prickly : the leaves cordate, having three, lour, or five-, longitudinal 

 Veins) they are alternate, dark green above, paler below, and rise from pretty long 

 round footstalks, from the baie of which come the branching spikes of flowers, which are 

 small ; the capsule is ob-ovate, leathery, three-sided, compressed into three wings, ac- 

 companied in the middle with a very narrow partition, to the inner edg< of which the 

 seeds are fixed ; these are irregularly triangular or roundish, and of a brownish red cu- 

 Vmr. The roots of tlii^ vine grow to a very large size, frequently weighing ten or eleven 

 pounds, and form a very valuable article of food either boiled or roastel. There are 

 two kinds of negro yam, known by the names of cassada-yani and man- yam, the latter is 

 considered tbe best, as being of a mealier better taste, and drier texture, but is not so pro- 

 ductive ; it is easily distinguished from the former by the stringy fibres which overspread 

 jts skin, which is smooth on the cassada-yam. The inside of both these yams is white, 

 of a viscous or clammy nature ; when roasted or boiled they are meally like apotatoebut 

 of a closer texture, tliey are a very pleasant and nourishing food, in much este m among 

 the negroes. When this yam is dug, a small piece of the top is cut olFand left upon the 

 vine, which is carefully moulded up, and in three monthsit produces another yam, com- 

 monly called the head, from which the plant is propagated, by cutting it into pieces, taking 

 care to leave an eye on each cutting, by which they germinate. These are planted on 

 little hillocks of earth dug about two feet distant from each other, generally two plants in 

 each hillock, from January to April, and the yams are fit for digging in August, Septem- 

 ber, and October. In each hillock a pole is planted six or tight feet long, for the vine 

 to run upon, and a field of them has much the appearance of a hop-garuen. Unless 

 the vine be supported it is thought that the yam will be dwarfish. These yams will not 

 keep for any length of time out of the ground, and should therefore be only dug as they 

 may be wanted for use. 



There is a variety of this species which grows wild in many parts of Jamaica, and com- 

 mon in Liguanea mountains ; the root of which is so bitter as to prevent its being eaten, 

 unless in cases of great necessity. It is yellow within, of a depressed form, having i.$ 

 edges dented as it were, 



2. ALK7L 



