COMMON RHUBARB. SENNA. 125 
found, in every respect, as efficacious as the best part of 
the roots : and the seeds possess nearly the same quali- 
ties. The leaves impart an agreeable acidity, somewhat 
similar to that of sorrel ; and a marmalade, which may, 
with advantage, be adopted for children, is made from 
the fresh stalks, by stripping off the bark, and boiling 
the pulp with an equal quantity of sugar. 
135. The COMMON RHUBARB (Rheum rhaponticum), 
is a plant which is cultivated in kitchen gardens, and has large, 
blunt and smooth leaves, and the leaf-statics fuir&wed on the 
upper side, cmd rounded at the edge. 
This species of rhubarb grows wild on the mountains 
of Rhodope, in Thrace, whence it was first propagated 
in other parts of Europe, about the year 1610. It is 
chiefly in request for the footstalks of' the leaves, which 
are used, (in the early part of the year, when there is 
little fruit) for pies and tarts. The root has some of the 
qualities of the true rhubarb, and has occasionally been 
imposed upon purchasers for that drug. 
CLASS X. -DECANDRIA. 
MONOGYNIA. 
136. SENNA is a drug, the dried leaves of an annual plant 
(Cassia senna) which grows in various parts of Africa and Asia. 
The stems of this plant are woody, and twt unlike those of a. 
shrub. The leaves are winged, and the leaflets oval, smooth, 
and jmnted. The flowers, which, grow in lengthened clusters, 
and are of pale yellow colour, are succeeded by oblong, compressed, 
and kidney-shaped pods. 
The cultivation of senna is carried on to considerable 
extent in Ethiopia, Arabia, Persia, and Upper Egypt, 
from several of which countries it has, from time im- 
