FAJVIILIES OF FLOWERING PLANTS 



137 



shape of the keel itself is found to vary; the peculiar snout-like shape 

 of the keel in the bean flower is well known. We shall follow the sys- 

 tematic arrangement of the tribes in this family, taking a hasty survey 

 of such genera as are of special importance. 



In the tribe Sophoreae the yellow-wood {Cladrastis lutea) of our 

 southern States, furnishes us both with a highly ornamental tree and a 

 yellow dye. Several exotic species of Sophora are cultivated in gar- 

 dens, while the South American 

 genus BIyroxylon yields a fine bal- 

 sam. 



Tribe Podalyrieae. This con- 

 sists mostly of shrubs with simple 

 or palmately divided leaves. It in- 

 cludes our various wild false iiidi- 

 goes {Baptisia) and the large Aus- 

 tralian genus Pulfenaea. 



Tribe Genisteae. In this group 

 are a number of well known Euro- 

 pean i)lants, such as the "golden 

 shower {Laburnum vulgare), the 

 Scotch whin or gorse {Ulex), the 

 broom {Cytisus scoparius), and the 

 woad- waxen or dyer's weed {Genista 

 tinctoria). Several of these have be- 

 come naturalized in the United 

 States; but the important American 

 genus of this tribe is Lupinus, the 

 lupines, comprising a large number 

 of species throughout the western plains and along the Pacific coast. 

 Fig. 120 shows the only lupine of the northeastern States {L. perennis). 

 In Florida occur two species with apparently simx)le leaves, but in 

 reality the leaf is a compound one reduced to a single leaflet, as shown 

 by the joint between blade and stalk. The genus Crotalaria is also a 

 large one, and widely distributed through warm regions. The inner 

 bark of C. juncea, the " sunn " or Bombay hemp of India, yields a valu- 

 able fiber. 



Tribe Trifolieae. This includes the true clovers {Trifolium), the 

 yellow hop-clover {Chrysaspis), the alfalfas {Medicago), and the sweet 

 clovers {3IeUlotus). In Europe are found also the "rest-harrows" 

 {Ononis), and the fenugreeks {Trigonella). All clover-like plants may 

 be known by the close heads or spikes of small flowers, and by the usu- 

 ally palmate leaves. Those of cold or alpine regions are usually her- 

 baceous, while those of the warmer temi^erate zone are often shrubs or 



Fig. 120. Wild lupine, Lupinus perennis. 

 After Britton & Brown, 111. Fl. Northeast. U. S. 



