THE PEA FAMILY, 127 



It differs from the preceding genus in having all 

 the stamens united together into a tube, which is, 

 however, cleft above. 



Many others have the tube cleft to the base ; but, 

 unlike genera of England, none appear to have the 

 tube entirely united from bottom to top and not cleft. 



Aspal'athus. — This large genus with about 150 

 species frequents dry, stony, and sandy places; and 

 in consequence of a deficiency of water are often of 

 a heath-like form and spiny. 



Erythri'na. — This plant has handsome scarlet 

 flowers, the standard (Fig. 50, 1, and II., s) being very 

 large in comparison with the size of the wings {w) 

 and keel (^). This has resulted from the dwarf- 

 ing of the latter since the stamens are not included, 

 but form the landing-place for the insect. They 

 are declinate, just as described in Pelargo'nmm. The 

 stamens are united as in the pea. 



From the photo, it will be seen how an insect 

 alighting on the projecting stamens will get dusted 

 below, when crawling into the flower. Subsequently, 

 on entering another flower in the same way, the 

 stigma {st) will hit it just where the pollen has been 

 retained from the previous flower visited. 



Medica'go (Lucerne). — This plant is not indige- 

 nous, but is so largely grown that it is worth while 

 repeating a peculiarity which can easily be observed. 

 It bears numerous little purple flowers. If a pencil- 



