3G7 
Rheum australe, Don* 
(B. Emodi, Wall. B. Webhianum, Eoyle.) 
Ilimalaian regions up to 16,00U feet. Drom this species at 
least a portion of the medicinal Rhuharh is obtained, most 
likely several species furnish Rhubarb-root, and its quality 
depends probaby much on the climatic region and the geo- 
logic formation, in which the plant grows. Should we wish 
to cultivate any species here for superior medicinal roots, 
then clearly localities in our higher and drier alpine tracts 
should be chosen for the purpose. Hayne regards the pre- 
sence of much yellowish pigment in the seed-shell as indi- 
cating a good medicinal Rhubarb-plant. As much as 5 lbs. 
of the dried drug are obtained from a single plant, several 
years old. An important orange-red crystalline substance, 
Emodin, allied to Crysophanic acid, occurs in genuine i 
Rhubarb. 
Rheum Rhaponticum, L. 
From the Volga to Central Asia. This species together 
with B. Tataricmn, L. fib, B. undulatuni, L., and a few others, 
all Asiatic (one extending to Japan) provide their acidulous 
leaf- stalks and unexpanded flower-mass for culinary pur- 
poses. Rhubarb leaves can also be used in the manner of 
Spinage. B. pahnatum, L., often considered to yield the 
best Rhubarb root, is an insular plant of North-eastern Asia, 
but may in the alpine deserts far inland become a source of 
the genuine root, so long ascribed to it. That is the only 
one with deeply jagged leaves. 
Rhus copallina, E- 
North America, extending to Canada. A comparatively 
dwarf species. This can also be used for tanning. A resin 
for varnishes is also obtained from this shrub. 
Rhus Coriaria, E-* 
The Tanner’s Sumach. Countries around the Mediterranean 
Sea. The foliage of this shrub or small tree, reduced to 
powder, forms the Sumach of commerce. Many localities 
in our colony are particulary well adapted for the growth 
of this bush. It is remarkably rich in Tannic acid, yielding 
