POLYPETALOUS COROLLAS. 



61 



Fig. 117 



Pig. 116 



Butterfly-shaped, Fig. 116. (Papilio- 

 naceous.) This corolla consists of four 

 separate petals, each of which has a dis- 

 tinct name. The upper and largest, is 

 called the banner, or standard. The two 

 side petals below, or under this, are called 

 the wings, or alas, and the lowest, placed 

 between these, and turned up like a boat, 

 is called the keel, or carina. That part 

 called the keel, contains the stamens and 

 pistils, which it encloses and defends from the weather. 

 Ex. Pea, Bean, Sweet Pea, (Lathyrus,) Senna. 



Prof. Lindley observes, that this tribe is not only among the 

 most extensive that are known, but also one of the most im 

 portant to man, with reference to the objects either of orna- 

 ment, of utility, or of nutriment. 



Cross-shaped, Fig. 117. Cru- 

 ciform corolla. It consists of 

 four petals, the borders of which 

 stand crosswise with respect to 

 each other. Ex. Radish, (Ra- 

 phanus,) Cabbage, (Brassica.) 



Plants bearing this kind of co- 

 rolla are distinguished by the 

 term cruciferous, or the cruciform 

 tribe. Many of them possess 

 acrid and stimulating qualities, as 

 Mustard, Horseradish, and Cress. These plants, when de- 

 caying, emit a peculiar animal odor, which is caused by the 

 azote, or nitrogen they contain, and which among plants is 

 an ingredient contained in no other tribe. 



NECTARY. (Nectarium.) 



This is the organ in plants which sometimes secretes the 

 honey, and hence is more commonly known under the name 

 of honey-cup. It is not, however, true that every appendage 

 known under the name of nectary, secretes honey, nor is the 



In the butter-fly shaped corolla, which is the banner, which the wings, 

 and which the keel ? What is said of the importance of the papilionace- 

 ous tribe of plants ? How many petals has the cruciform corolla, and 

 how are they placed with respect to each other ? What does the term 

 nectary strictly signify ? Does every part called nectary, contain honev ? 

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