438 FORAGE PLANTS AND THEIR CULTURE 



as California bur clover, as it is especially abundant in 

 that state. It was early introduced into California, where 

 it has become widespread and proven valuable for pastur- 

 age both on cultivated and on range lands. The same 

 species is also abundant in Argentina, Chile and Australia. 

 The burs get caught in the fleece of sheep, and in recent 

 years seed has been saved and cleaned in Europe from 

 the rubbish taken out of wool. 



While toothed bur clover is most abundant in Califor- 

 nia, it also occurs in Washington and Oregon, and to some 

 extent in the Southern States. In the latter region it is 

 not as well adapted as spotted bur clover, and instances 

 are known where the toothed bur clover was winter-killed 

 when the spotted was uninjured. 



Toothed bur clover can hardly be called a cultivated 

 crop, but where it persists it furnishes a large amount of 

 pasturage, both on cultivated and on uncultivated land. 

 Even after the burs are ripe and dry they are eaten eagerly 

 by sheep. A considerable amount of bur clover seed is 

 harvested incidentally with wheat in California, and from 

 this source all of the American-grown seed is obtained. 



There are several varieties of toothed bur clover , differ- 

 ing in the character of the fruits, two of them having spine- 

 less burs; namely, confinis with 3 coils, and reticulata 

 with 5 coils to the pod. 



Spotted bur clover. Spotted bur clover differs from 

 toothed bur clover in having a dark purple spot on each 

 leaflet, and in the pods being beset with longer and softer 

 bristles and the edges of the coils furrowed. A spineless 

 variety, inermis, is also known. 



Spotted bur clover is less abundant in California and 

 more plentiful in the Southern States than toothed bur 

 clover. This may be partly incidental to earlier introduc- 



