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, 6, is afiower of the genus Rheum. 



We have dwelt somewhat at length upon exotics, because they 

 are seldom described in botanical w^orks 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, Monadelphia, 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 Jirst 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 CasBia Jistula, 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 seima 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 A'hich the flowers 

 aave ten stamens?— Order Monogynia— Wild Indigo— Cassia. 



