162 
CLASS DECANDRIA. 
ference ; the root grows to a great size ; some roots have been im- 
ported from Turkey which weighed more than seventy pounds. At 
Fig. 133, &3 is a flower of the genus Rheum. 
We have dwelt somewhat at length upon exotics, because they 
are seldom described in botanical works in common use. If you be- 
• come interested in the study of plants, you will naturally wish to 
know something about those which you are in the habit of using for 
food, or medicine, or to which, as in the laurel of the ancients, allu- 
sions are often made in the books which you read. But you cannot 
become practical botanists without much observation of our native 
plants. You must seek them in their own homes, in the clefts of 
rocks, by the side of brooks, and in the shady woods ; it is there you 
will find nature in her unvitiated simplicity. We do not go to the 
crowded city to find men exhibiting, undisguisedly, the feelings of 
the heart. The flower transplanted from its rural abodes, exhibits 
in the splendid green-house, a physical metamorphosis, not less re- 
markable than the moral change which luxury too often produces 
upon the character of man. 
LECTURE XXIX. 
CLASS X. — DECANDRIA. 
Plants of this class have ten stamens, but this circumstance alone 
would not distinguish them from some of the other classes ; the 
number of stamens must not only be ten, but these must be distinct 
from each other ; that is, neither united by their filaments below, nor 
by their anthers above. Other classes, Monadeiphia, Diadelphia, 
Gynandria, and the two classes with the stamens and pistils on 
separate flowers, may also have ten stamens ; but circumstances 
respecting the situation of these organs distinguish these classes 
from each other. 
Order Monogynia^ 
In the first Order of the tenth class, we 
find some plants with papilionaceous corol- 
las ; these, because their filaments are not 
united, are separated from the natural family 
to which they belong, and which are mostly 
in the class Diadelphia. Among those which 
are thus removed from the class where from 
their general appearance they might have 
been looked for, is the wild indigo, (Baptisia,) 
a handsome plant with yellow flowers, two 
or three feet in height, and very branching; 
the stem and leaves are of a bluish green. 
This is found in dry sandy woods; it was 
used as a substitute for indigo during the time of the American rev- 
olution. 
The Cassia, fistula, a native of the Indies contains in its legume a 
pulp 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, One species, the Cassia 
marylandica is called American senna, on account of its medicinal 
Concluding remarks— Are there any classes except the tenth, in which the flowers 
*sve ten stamens?— Order Monogynia— Wild Indigo— Cassia. 
