Annual yellow sweet clover, more commonly known as sour clover or
bitter clover, is found chiefly in the South and Southwest. This plant
is considered a noxious weed in grain fields throughout the Southwest.
It is claimed that the flavor of the seed which is imparted to wheat
can not be removed. Bakers decidedly object to this flavor, stating
that it injures bread. Sour clover is grown rather extensively as a
green-manure crop in orchards in portions of Arizona and southern
California and when properly handled in these regions it has given
profitable results. As the seed is obtained from the screenings of
wheat, it is offered on the market at a very low price. Occasionally it
is sold for the yellow biennial sweet clover. Seed of this plant should
not be sown in any part of the United States except the extreme South
or Southwest, and then only as a green hay manure crop. Where it is
desired to plant sweet clover for pasturage or for the biennial white
or biennial yellow species should be used.