CLASSIFICATION OF DICOTYLEDONS. 209 



the Papilionacece are climbers, either having twining stems, as 

 in the common beans, or else with part of the leaf changed 

 into a tendril as in the pea (Fig. 115, A) y vetch, etc. The 

 leaves are usually compound. 



Of the second family (Ccesalpinece), mainly tropical, the honey 

 locust (Gleditschia) and red-bud (Cercis) (Fig. 115, (2) are 

 the commonest examples. The flowers differ mainly from the 

 Papilionacece in being less perfectly papilionaceous, and the 

 stamens are almost entirely distinct (Fig. 115, H). The last 

 family (Mimosacece) is also mainly tropical. The acacias, 

 sensitive-plant (Mimosa), and the sensitive-brier of the south- 

 ern United States (Schrankia) (Fig. 115, /) represent this 

 family. The flowers are quite different from the others of 

 the order, being tubular and the petals united, thus resembling 

 the flowers of the Sympetalce. The leaves of Mimosa and 

 Schrarikia are extraordinarily sensitive, folding up if irritated. 



