378 ILLUSTRATIONS OF THE BOTANY OF [Dioscoree, 
a fecula is separated in the same manner that sago is, and like it employed as an article 
of diet by the inhabitants of the Malayan and Molucca islands. In Otaheite and other 
Society islands, they make cakes of the meal of the tubers of 7. pinnatifida, which are 
the tacca youy of some navigators: they form an article of diet in China and Cochin- 
China, as also in Travancore, where, Dr.Ainslie informs me, they attain a large size, 
and that the natives eat them with some acid to subdue the acrimony. 
175. DIOSCORE. * 
The Dioscoree form a small family, allied to Smilacee, but from which they are 
distinguished as well by their inferior ovary as by their capsular fruit. The genera 
are few in number, and of these, Zamus is only allied to this family by its inferior fruit, 
and, by this being a berry, to Smilacee. The genus is, moreover, found in Europe and 
the north of Africa, as well as in the temperate parts of Asia, such as the Tauro-Caucasian | 
region. Rayania is a West-India genus, and Oncus a little-known Cochin-Chinese one. 
Dioscorea, therefore, alone remains to be treated of; and, as the most numerous in 
species, is also the most widely diffused through the tropical parts of the world; it 
extends also south to the Cape of Gdod Hope, where is found Testudinaria elephantipes, 3 
(now usually referred to this genus,) and also to New Holland, whence several new 
species have been described by Mr. Brown. To the north species are found in the 
United States of America, and in the most northern parts of India, as well as on the 
Himalayan mountains. The species are, however, most numerous in the hottest parts 
of the world; but from their numbers, varying forms, diecious nature, and the 
want of authentic specimens, it is difficult to ascertain the identity of species found in 
different parts of the world. Rheede and Rumphius have figured some; Roxburgh 
has described more; and of these, several are contained in the E. I. Herbarium. 
D. pentaphylla, demonum, alata, rubella, aculeata, and nummularia, are species found 
in the Malayan islands, as well as in the southern parts of India. Of these, D. penta- 
phylla occurs also in Central India, as I have received specimens from Mr. Malcomson, 
from near Nagpore, where it is called yeller-guddoo ; and another species, named chunchoo- 
guddoo. In the most northern parts of India, the most common species is D. sagittata, 
nob., nearly allied to D. sativa, Wall. Cat. 5108. D. versicolor, Ham., genthee of the 
natives, is extremely common about Lohargaon, in Bundlecund, and partly also in the 
Peninsula of India, as well as all along the foot of the Himalayas, and as high as 
5,000 feet in the neighbourhood of Jurreepanee. D. virosa is an Himalayan species, 
called ramberee by the natives in Gurhwal and Sirmore; another, very elegant in 
appearance, has been named D. deltoides by Dr.Wallich from Nepal, and which | 
obtained on Mussooree and Dhunoultee, and from Gorakhotee, near Rampore, in 
Lower Kunawur. 
The species of this family are important in tropical countries, on account of their 
large tubers abounding in nutritious fecula, which is employed as food. These tubers 
are well known by the name of yams; though those of Zacca and of Arum are some- 
times 
