EUCALYPTUS TREES. 261 
confectionery ; the roots are of medicinal use, Only 
in our Alps would this herb fully establish its value. 
The root is biennial, and used in the distillation of 
some cordials. 
Arctostaphylos uva ursi, Sprengel.— Alpine and arc- 
tic Europe, North Asia, and North America. A me- 
dicinal, small shrub, which here could best be reared 
in the heath-moors of our Alpine regions. 
Argania Sideroxylon, Roem. and Schult.—Tne Ar- 
gan-tree. Western Barbary, on dry hills. Its growth 
is here found to be slow ; but it is a tree of longevity. 
Though comparatively low in stature, its foliage oc- 
casionally spreads to a circumference of 220 feet. It 
sends out suckers from the root. The fruits serve as 
food for cattle in Morocco; but here the kernels 
would be more likely to be utilized by pressing the 
oil from them. 
Aristolochia Serpentaria, L.— The Snake - root of 
North America. The root of this trailing herb is 
valuable in medicine ; it contains a peculiar volatile 
oil. Several other Aristolochize deserve culture for 
medicinal purposes, for instance, Aristolochia ovali- 
folia (Guaco), and A. anguicida, from the mountains 
of Central America, should they prove hardy. 
Arnica montana, L.—Colder parts of Europe. This 
pretty herb is perennial, and of medicinal value. It 
is eligible for our sub-alpine regions. The active 
principles are, arnicin, volatile oil, cupron, and cap- 
ryl acid. 
Arracacha xanthorrhiza, Bancroft. — Mountain re- 
gions of Central America. An umbelliferous herb. 
The roots are nutritious and palatable. There are 
yellow, purple, and pale varieties, 
