west, inland, to Nebraska, south into Mexico, and on the Pacific 

 coast northward to Washington. 



In California, this species is a winter annual ; the seeds germinate 

 after the fall rains and the plant matures at the end of the rainy 

 period in May or June. In the Southwest and inland it makes 

 most of its growth in the spring, but in the moist South and East, 

 under normal conditions, it grows throughout the spring and sum- 

 mer. This species inhabits practically all soils, such as sands, stony 

 loams, and adobe, provided they are moist, but not wet. All ex- 

 posures are invaded, and it does well under light conditions vary- 

 ing from full sunlight to heavy shade. However, it is a plant of 

 the valleys and low foothills, occurring only as scattered individuals 

 in the ponderosa pine belt of the Western States. In the Southwest 

 and on the Pacific coast it is commonly associated with annual weeds 

 and grasses. In California, the plant may occur in pure stands, 

 but more often is associated with other winter annuals, such as 

 bromegrasses, wild oats, and various species of alfileria. 



California bur-clover is one of the most valuable annual forage 

 plants on the Pacific coast, 1 even though the green foliage has a some- 

 what bitter taste. Once accustomed to this peculiar taste, all classes 

 of livestock, except horses and mules, eat it greedily, especially when 

 it is maturing. 2 At this time it is very nutritious and, where abun- 

 dant, often serves as a finishing feed for lambs. However, excessive 

 use of the green, dew-coated foliage sometimes causes bloat in live- 

 stock unaccustomed to grazing it regularly. Because of the abundant 

 and nutritious burs, this species provides a summer and fall feed 

 superior to that of other common annuals ; sheep especially, seek the 

 fallen burs. This close use is probably most common after the spiny 

 burs have been softened by the fall rains. However, during summer, 

 the burs accumulate in the wool as numerous mats which decrease the 

 value of the clip. 



Chemical analyses indicate that California bur-clover is very simi- 

 lar to alfalfa in forage value, and definitely superior to the former's 

 common annual range associates, especially in protein and phos- 

 phorus content. 3 Like other forage plants, bur-clover loses nutritive 

 value by excessive exposure to moisture and light after it cures on 

 the range, although the burs are not appreciably affected. 4 Leach- 

 ing and bleaching reduce the digestibility of all nutrients except 

 crude fiber, and the loss of soluble constituents causes decreased 

 palatability. 



California bur-clover is a common constituent of wild hay, espe- 

 cially in California, although the cutting is limited to sites where 

 it is upright due to its own abundance or the density of other plants. 

 Bur-clover is invaluable as a cover crop or green manure 2 both in 

 western orchards and throughout the Cotton Belt. It is especially 



a Jepson W L. A MANUAL OF THE FLOWERING PLANTS OP CALIFORNIA. 1,238 pp., illus. 

 Berkeley, Calif. [1925.] 



2 Piper, C. V. BUR CLOVER. U. S. Dept. Agr. Farmers' Bull. 693, 14 pp., illus. 1915. 



3 Hart, G. H., Guilbert, H. R., and Goss, H. SEASONAL CHANGES IN THE CHEMICAL 



COMPOSITION OF RANGE FORAGE AND THEIR RELATION TO NUTRITION OF ANIMALS. Calif. 



Agr. Expt. Sta. Bull. 543, 62 pp., illus. 1932. 



4 Guilbert, H. R., and Mead, S. W. THE DIGESTIBILITY OF BUR CLOVER AS AFFECTED BY 

 EXPOSURE TO SUNLIGHT AND RAIN. Hilgardia 6 : 1-12. 1931. 



