EUCALYPTUS PREES. 997 
Daucus Carota, L.—The Carrot. Europe, North 
Africa, extra-tropic Asia, east to Japan. Admits of 
naturalization along our shores. Beyond the ordinary 
culinary utilization it serves for the distillation of a 
peculiar oil. The chemical substances carotin and 
hydrocarotin are derived from it. 
Digitalis purpurea, L.— Greater part of Europe. 
The Foxglove. A biennial, and exceedingly beau- 
tiful, of great medicinal value, easily raised. Chem- 
ical principles: digitalin, digitaletin, and three pecu- 
liar acids. 
Dioscorea aculeata, L.*—The Kaawi-Yam. India, 
Cochin-China, South Sea Islands. Stem prickly, as the 
name implies, not angular. Leaves alternate, undi- 
vided. It ripens later than the following species, and 
requires no reeds for staking. It is propagated from 
small tubers. This yam is of a sweetish taste, and 
the late Dr. Seemann regarded it as one of the finest 
esculent roots of the globe. A variety of a blueish 
hue, cultivated in Central America (for instance, at 
Caracas), is of very delicious taste. In the warmest 
parts of our colony this and the following species are 
likely to come to perfection: 
Dioscorea alata, L.*—The Uvi-Yam. India and 
South Sea Islands. The stems are four-angled and 
not prickly. The tubers, of which there are many 
varieties, will attain, under favorable circumstances, 
a length of 8 feet, and the prodigious weight of 100 
pounds! This species and the preceding one are the 
two principal kinds cultivated in tropical countries, 
D. alata is in culture supported by reeds. It is prop- 
agated from pieces of the old root, and comes to per- 
fection, in warm climes, in about seven months. The 
