Yellow sweetclover, also known as biennial yellow sweetclover and 

 yellow melilot, is native to Europe and Asia but now widely natu- 

 ralized in North America. It is a large herbaceous biennial closely 

 resembling white sweetclover although not so tall and with a more 

 spreading habit of growth. Its common name comes from the 

 cloverlike leaves and fragrant yellow flowers; its blossoms yield a 

 sweet nectar that is especially attractive to honeybees. The specific 

 name officinalis arises from the use of its dried leaves and flowering 

 tops in pharmacy; the plant, like other members of this genus, con- 

 tains coumarin (a vanilla substitute) and nielilotic acid. 1 



This sweetclover has spread throughout the United States and 

 the southern half of Canada; it is almost as widely distributed as 

 white sweetclover but only rarely is as abundant. 2 Yellow sweet- 

 clover is even less common than white sweetclover on the mountain 

 ranges of the West, but occurs sparsely at the lower elevations along 

 streams. This species has been cultivated both for pasture and hay 

 and, in many farming areas where it has escaped .from cultivation, 

 now is a common and prolific weed. The plant has established itself 

 abundantly in semihumid or humid areas on abandoned farms, 

 eroded hillsides, and along fence rows, railroads, and highways; it 

 also inhabits many such infertile sites as cuts and barrow pits, where 

 the surface soil has been removed. 



Yellow sweetclover makes more rapid growth, maturing from one 

 to two weeks earlier, and produces more seed than white sweetclover. 3 

 Its resistance to heavy use, aggressiveness, greater tolerance to heat 

 and drought, and its ready adaptability to poorer soils are desirable 

 characteristics. The species is even less exacting than white sweet- 

 clover in soil and climatic requirements, being, among other things, 

 more drought-resistant and winter-hardy. It is better qualified to 

 succeed in dry weather and, for this reason, may be more effective 

 than white sweetclover in soil-improvement projects in areas where 

 it is adapted. Yellow sweetclover is preferable for pasturage in the 

 western mountain sections, since, unlike white sweetclover, it ma- 

 tures seed even under moderately heavy utilization. Its lower, more 

 spreading growth insures production of some flower heads fairly 

 close to the ground. If the stand is pastured, the lower flowers are 

 not usually cropped by grazing animals but are left to reseed natur- 

 ally ; consequently, the yellow biennial maintains a permanent stand 

 from year to year. 4 6 This species has not been used extensively in 

 reseeding depleted ranges; potentially, however, it may prove valua- 

 ble for that purpose. 3 Although white sweetclover alone was used 

 in reseeding experiments on burned-over land at Sandpoint, Idaho, 

 probably the yellow-flowered species would be even better able to 

 withstand intensive cropping by livestock. 6 It is equally important 



1 Youngken, H. W. A TEXT BOOK OF PHARMACOGNOST. 538 pp., illus. Philadelphia. 

 1921. 



2 Piper, C. V. FORAGE PLANTS AND THEIR CULTURE. Rev., 671 pp., illus. New York. 

 1924. 



3 Forsling, C. L., and Dayton, W. A. ARTIFICIAL P.ESEEDING ON WESTERN MOUNTAIN 

 RANGE LANDS. U. S. Dept. Agr. Circ. 178, 48 pp., illus. 1931. 



*McKee, C. GROWING AND USING SWEET CLOVER IN MONTANA. Mont. Agr. Expt. Sta. 

 Circ. 118, 31 pp., illus. 1923. 



B Hulbert, H. W. SWEET CLOVER: GROWING AND HANDLING THE CROP IN IDAHO. Idaho 

 Agr. Expt. Sta. Bull. 147, 20 pp., illus. 1927. 



6 Christ, J. H. RESEEDING BURNED-OVER LANDS IN NORTHERN IDAHO. Idaho Agr. Expt. 

 Sta. Bull. 201, 28 pp., illus. 1934. 



