Minnesota Plant Life. 299 



The sweet clovers are represented in Minnesota by two 

 varieties, the white sweet clover and the yellow. These are 

 bushy, branching herbs sometimes eight or nine feet in height. 

 The small flowers are arranged in slender racemes. The pods 

 are short-ovoid, and often unlike most legumes fail to open. 

 The peculiar fragrance of the flowers indicates adaptation to 

 insect pollination. 



Six or seven kinds of clover, only one of which is native, 

 occur throughout the state. These are plants with leaves com- 

 posed of three leaflets, and flowers aggregated on short pedicels 

 in more or less globular or elongated heads. The flowers at 



FIG. 147. Sweet-clover bushes. After photograph by Williams. 



the edge of the head mature first, and, as they are pollinated, 

 often curve downwards, leaving the field clear to the unpol- 

 linated flowers to attract insects. The pods of the clovers, like 

 those of the sweet clovers, often fail to open, and, when they do, 

 separate along only one of the margins. If it were not for the 

 butterfly-shaped flowers such plants might escape classification 

 as pulses. The three most common clovers in the state are the 

 prostrate, with branches lying upon the ground, the common 

 white, and the red clover. The flowers of the prostrate clover 

 are yellow. Besides these, there are a few other introduced 

 clovers, one of which may be known by its oblong heads 



