THE PEA FAMILY. 



123 



of the stalk. These take the form of thorns in 

 Acacias, etc. 



The order is first divided into three " Sub -orders " 

 as follows, each of which has its '' Tribes " : — 



Fig. 46.— II. Calyx, III. Vertical section of flower. IV. Stamens and 

 pistil. V. Diagram. VI. Legume. 



I. Papilionaceae. — This tribe is so called from the 

 fancied resemblance to a butterfly (Latin ixiinlio) in 

 the irregular corolla. 



II. CaesalpinesB. — Though the flowers are irregular, 

 they are difterent in form from those of the first. , 



