PLANTS CULTIVATED AT CARACAS. 265 
(tubers egg-shaped, inside yellowish and very mealy ; peel very thin, 
reddish; buds deeply sunk into the tuber and very numerous), culti- 
vated formerly in the valley of Caracas, has now disappeared com- 
pletely, partly destroyed by the murrain, partly lost by the carelessness 
of the cultivators, who did not keep up the pure stock. It was pro- 
bably of New Granadian origin. The potato, cultivated at present, is 
derived from North American or German seedlings, but it suffers much 
from the murrain. Mosquera, in his ' Compendio de Geografia de 
los Estados Unidos de Colombia,' London, 1866, p. 38, mentions a 
wild species of Solatium, which he takes for the true tuberosum, in 
the mountains of the upper valley of the Cauca, in the country of the 
Coconuco Indians. It has no tubers, or at least very few, but, when 
cultivated, it produces the best varieties of potatoes. (" Cultivada 
esta planta, se obtienen las variedades de patatas hasta las mas buenas 
que se conocen. ) 
Manihot utilissima, Pohl. — One of the original bread-yielding plants 
of this country, and even to-day abundantly cultivated under the 
Haytian name ' Yuca.' I have carefully examined the different varie- 
ties cultivated in the valley of Caracas, and found them to belong all to 
M. utilissima, Pohl (" ovario alternatira inrequaliter 6-gono glabro, cap- 
sulis inrequaliter anguste alatis, alis undulato-subcrenatis," Dr. Miiller- 
Arg. in De Cand. Prod. xv. 1064). The poisonous varieties are called 
' Yuca amarga/ in opposition to the c Yuca dulca,' or 'boimita.' It 
appears from a curious passnge in Oviedo (Sumario de la Natural His- 
toria de las Indias, ed. Rivadenevra, in Bibl. de Aut. Kspaiioles, 
torn. xxii. p. 477), that the latter was exclusively cultivated on the 
mainland (" en Tierra Firme toda la yuca es de esta boniata"). There 
are several forms of ■ Yuca dulce,' of which I add a diagnosis : 
I. Stems and leafstalks reddish. 
' a. Broad-leaved (leaflets at least 1 inch broad) ; lateral nerves forming 
an angle of 60 to 65 degrees with the principal nerve ; sinus be- 
tween the leaflets open. 
a. Leaves obovate-acuminate. Yuca algodona. 
£. Leaves elliptical-acuminate. Y negrita. 
b. Narrow-leaved (leaflets seldom more than \ inch broad) ; lateral 
nerves forming a nearly right angle with the principal nerve ; 
leaflets on the basis touching or even overlapping each other, 
sinns therefore not open. Y. vnrlbita. 
H. Stems and leafstalks not reddish. Y. blanqulta. 
