32 LUPINUS. 



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

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

 species 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 

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

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

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

 (Prosopis juliflora] and Screw-pod Mesquit, or Tornilla (P. pube*cens), are small trees of 

 Southern California. Prosopis and Acacia belong to the suborder Mimosse. All the 

 plants here described (except Cercis) belong to the suborder Papilionaceae, which is 

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



The devices for securing cross-fertilization in this order are often very remarkable. 

 Key to genera and species, p. 104. 



LUPINUS. 



A. Perennials, more or less shrubby. 



Li. jucundus, Greene. Long peduncled racemes: keel naked, banner notably smaller 

 than the other petals. 



L. eminens, Greene. Almost arborescent: short and dense racemes, short ped- 

 uucled: pods villous, nearly erect, about 4-seeded. 



L. variicolor, Steud. Woody basal branches short, slender: raceme short: flowers 

 large: keel ciliate, pods large. 



The above, with L. albifrons, Benth., may be considered as varieties of Li. Cham- 

 issousis, of which Greene says, "Apparently confined to the sand dunes of the San 

 Francisco peninsula and Pt. Reyes. 



Li. propinquus, Greene. Near L. arboreus, but small: racemes short: petals 

 violet. A seaboard species. 



B. Perennial herbs: flowers large. 



Li. formosus, Greene. Leaflets 7-9, linear -lanceolate, very acute: flowers rich 

 violet: keel naked. Common in fields. 



Li. sericatus, Kellogg, A foot or less in height, silky-canescent, leafy; leaflets 7, 

 spatulate oblong: keel slender, pointed, lightly ciliolate. In the Mt. Helena region: 



Li. latifolius, Agardh. Erect, 2-4 feet high, the stem dark green and shining* 

 leaflets 5-7, broadly oblanceolate, thin, ciliolate: blue flowers changing to dull brown. 

 Has been considered a form of L. rivularis. 



