240 NATURAL HISTORY OF THE FARM 
Fic. 90. Rabbitt’s-foot 
clover (after Britton and 
Brown). 
imported true clovers of very different 
appearance: the tall, branching, rab- 
bit’s foot clover, with its whitish corollas 
hidden among long and silky calyx 
lobes, which, combined together in the 
soft heads, suggest the name it bears; 
and two delicate little yellow-flowered 
hop-clovers. 
The sweet clovers are two species of 
tall fragrant roadside weeds, similar in 
appearance except that one bears white, 
and the other yellow flowers. The white 
sweet clover (fig. 88) is able to follow the 
road grader and take possession of and 
thrive in the 
hardest and most 
unpromising of 
soils. 
The medics 
differ from the sweet clovers in 
having bent or spirally twisted pods, 
instead of straight ones. They also 
have shorter flower clusters. One of 
them, alfalfa, is of vast importance 
as a forage crop. It has purple 
flowers. Theothersare unimportant, 
yellow-flowered species that we find 
in waste places. 
Of all the array of clovers, only the 
white clover and a few of its nearest 
allies in the genus Trifolium are 
native American plants. But all of 
them are interesting and worthy of 
a little careful study. 
Fic. 91. Yellow-hop clover. 
