lo6 
CLASS DECANDEIA 
medicinal I'hubarb ; this is obtained from the roots, which arc 
thick, fleshy, and yellow. In this root are rapliides of oxalate 
of lime, which yield a large proportion of rhubarb. At Fig. 
140, 5, is a flower of the genus Rheum. 
a. In becoming interested in the study of plants, we naturally wish to know 
Bomething about tliose which we are in the habit of using for food or medicine, or 
to which, as in the laurel of the ancients, allusions are often made in the bo'^ks 
we read. But no one can become a practical botanist without much observation of 
native plants. They must be sought in their own homes, in the clefts of rocks, by 
the side of brooks, and in the shady woods ; it is there we find nature in her un- 
vitiated simplicity. We do not go to the crowded city to find men exhibiting, un- 
disguisedly, the feelings of the heart ; and the flower transplanted from its rural 
abodes, often exhibits in the green-house a metamorphosis which conceals its real 
character. 
LECTUEE XXIX. 
DECANDEIA, TEN STAMENS. 
215. The number of stamens in plants of this class must nor 
only be ten, but these must be distinct from each other ; that 
is, neither united by their filaments nor by their anthers. 
Other classes may also have ten stamens ; but circumstances 
respecting the situation of these organs distinguish these classes 
from each other. 
216. Order Monogynia., one pistil. — We here find some plants 
with, papilionaceous corollas j these, because Xhfdiv filaments are 
not united., are separated from the natural family to which they 
belong, and which are mostly in the artificial class Diadelphia. 
The wild indigo i^Baptisia) has ten stamens, distinct ; yellow, 
papilionaceous flowers, and leguminous fruit. This plant be- 
comes black in drying. The Cassia fistula., a native of the 
Indies, contains in its legume a pulp secreted from the endo- 
carp which is much valued in medicine, and known by the 
name of cassia. The Cassia senna furnishes the senna used in 
medicine ; this species grows in Egypt and Arabia. Cassia 
maryUmdica is called American senna on account of its medici- 
nal qualities. Cassia nictitans has small yellow flowers and 
beautiful pinnate leaves ; it is called the American sensitive- 
plant, as it closes its leaves when touched, and folds them at 
night. A plant, called, by the Indians, red-bud (Cercis cana- 
densis)., belongs to this class, and to the great natural fam 
ily, Leguminosce. It is a large tree, appearing early in spring, 
laden with clusters of fine crimson flowers, resembling at a 
a. Remarks.— 215. Is there any class except the tenth in which the flowers have ten stamens 1 - 
918 Order Mouogynia— Wild Indigo — Cassia — Cercis. 
