38b 



LEGUMINOS-E. (PEA FAMILY.) 



Fig. A. At a is seen a single flower of Lupinus Dov^ 

 glasii; b, the same with the upper and side petals re- 

 moved, showing the united pair of long-clawed, lower 

 petals and the base of the stamineal tube. 



Fig. B. a. The same flower with all the petals re- 

 moved, showing the united stamens, 5 of which hava 

 shed the pollen and crinkled down. 6. The stamens as 

 they appear in a bud. The shorter stamens of the bud 

 become the longer stamens of the flower, c. Anther of 

 a long stamen in a magnified, d. Anther of a long 

 stamen in 6 (short in a) magnified. 



order, the species within the United States numbering about 150, nearly all of which 

 belong west of the Kocky Mountains. We have about 25 kinds of clover; only 3 or 4 

 sjjecies are natives of the East. Hosackia, numbering 28 species in our whole country, 

 25 of which grow here, is not represented in the East at all. On the other hand, the 

 large genus Desmodium, numbering in the East 19 species, has no representative west of 

 the Rocky Mountains. Pickeringia is probably not found beyond the boundary of Cali- 

 fornia. The great Australian genus Acacia, numbering there nearly 300 species, is 

 represented in Southern California by a small tree {A. Greggii), and in the East by an 

 herb. Possibly 30 species are cultivated for shade trees. Honey Mesquit, or Algaroba 

 {Prosopis julifiora) and Screw-pod Mesquit, or Tornilla ( P. puhescens), are small trees of 

 Southern California. Prosopis and Acacia belong to the Suborder Mimoseae. All the 

 plants here described (except Cercis) belong to the Suborder Papilionaceae, which is dis- 

 tinguished by flowers, like those of the pea, as before described. 



Cercis, which, by mistake, is not described in the proper place, belongs to the Sub- 

 order Csesalpineae, in which the side petals enclose the upper one and the stamens are free. 



§ 1. Stamens distinct. ^ 



Leaves digitately 3-foliolate. Herbs; yellow flowers Thermopsis. 1 



Shrub; purple flowers Pickeringia. 2 



Leaves unequally pinnate; shrubby; 1 petal Amorpha. 9 



§ 2. Stamens all united into a sheath. 



Anthers of two forms; leaves digitate, more than three leaflets Lupinus. 3 



Anthers all alike; leaves pinnately 3-foliolate Psoralea. 8 



§ 3. Stamens diadelphous [2 sets, and 1). 

 * Leaves S-foUolate; pods small. 



Flowers capitate. Corolla persistent Trifolinm. 4 



Flowers in axillary racemes or spikes. Pod globular, wrinkled Melilotus. 5 



Flowers in axillary spikes. Pod one-seeded Psoralea, 8 



Pod spirally coiled or reniform Medicago. 6 



