An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
WHITE SWEETCLOVER-Melilotus albus Desr.
DESCRIPTION-A tall erect hairless annual or biennial, rarely perennial, which reproduces only by seeds. The stem is erect, branching above 1 to 6 feet high. The leaflets are similar to those of annual yellow sweetclover. The flowers are also similar, but are white instead of yellow, and larger, about 1/5 inch long. They are likewise arranged in long narrow spikelike clusters along the upper half of the flower stalks, but the stalks are 2 to 8 inches long. The pods are slightly larger, 1/12 to slightly more than 1/8 inch long. The seed is oblong to oval, about 1/12 inch long, notched near one end, yellowish green to brown, with a smooth, not roughened surface.
DISTRIBUTION-White sweetclover was introduced from Eurasia. As a weed it is not as serious as annual yellow sweetclover. A pest in cotton, alfalfa, grapes, and in field ends and borders of cultivated fields; also in other cultivated crops. It is a common weed in moist sandy soil, scattered throughout most of the state along roadsides, ditches, fences, and creeks; 100 to 7,500 feet elevation; flowering March until October.
Both white sweetclover and annual yellow sweetclover are excellent honey plants. The herbage is very fragrant when dried, but has a peculiar odor when fresh. They rate high in forage value, and animals soon acquire a taste for them.
YELLOW SWEETCLOVER-Melilotus officinalis (L.) Lam.
DESCRIPTION-Very similar to white sweetclover, but the flowers are yellow and the stems are less erect and not as stout. Not as common nor as widespread in Arizona as annual yellow sweetclover or white sweetclover.
Copyright (c) 1972 The Arizona Board of Regents