Spring larkspur, a perennial herb, probably the most widely dis- 

 tributed of the low larkspurs, ranges from British Columbia to 

 extreme northern California, New Mexico, and Montana. Its most 

 abundant growth is probably in Colorado and Utah, though it is 

 very common in Idaho, Montana, Oregon, Wyoming, and New 

 Mexico. It is typically a plant of the mountains, growing at alti- 

 tudes from 1,000 feet or so in northwestern California and in the 

 northern and northwestern parts of its range up to elevations at 

 least as high as 10,500 feet in the Rocky Mountains, especially the 

 more southern portion. The species grows in numerous associations, 

 in aspen, openings in lodgepole pine, and in the sagebrush, oakbrush, 

 and ponderosa pine belts, but is especially characteristic of open 

 grass-weed-brush areas. Frequent associates are lupines, blue- 

 grasses, wheatgrasses, and rabbitbrushes. It inhabits a variety of 

 soils dry to moist, shallow and sandy, gravelly, or rocky, to deep 

 rich loams or heavy clays. 



Spring larkspur causes heavy losses of cattle on the spring and 

 early summer ranges. This poisonous species is probably the most 

 destructive of the low larkspurs. It is widely distributed, occurs in 

 dense masses, grows in a variety of soils, and is readily grazed. 

 Most of the United States Department of Agriculture experiments 

 with low larkspur have been concerned with this species. 1 The 

 formula of the recommended remedy and the methods of its use are 

 presented in detail in the genus notes (W58). 



No known losses of sheep or horses have occurred on the range 

 from spring larkspur poisoning. This species is more palatable to 

 sheep than to cattle and is sometimes grazed rather extensively by 

 both classes of livestock when little other feed is available. Sheep 

 generally prefer grasses and other weeds to the low larkspurs, and 

 on some ranges in Idaho and Nevada spring larkspur is regarded as 

 unpalatable to livestock. Due to the early seeding and subsequent 

 dying down of spring larkspur on the range, it is usually safe to 

 graze cattle after the first of July on areas which produce large 

 quantities of this species, unless normal plant development is delayed 

 by unfavorable weather or other conditions. 



Although low larkspurs are somewhat similar in appearance to 

 tall larkspurs, their solitary stalks and low growth distinguish them 

 from the tall larkspurs. The leaves of low larkspurs are few in 

 number and are more finely dissected than those of most tall lark- 

 spurs. As the common name spring larkspur indicates, this plant 

 starts growth early, sending up a single, short (rarely 2 feet high), 

 sparingly leafy stem with usually clustered, tuberous roots ; the stalk 

 generally branches somewhat near its base. The showy, dark blue 

 or purplish (rarely white) flowers open in May or early June; seed 

 forms in late June or early July, varying with the elevation or sea- 

 sonal and site conditions. After seeding, the plant dries up and 

 disappears. 



1 Marsh, C. D.. Clawson, A. B., and Marsh, H. LARKSPUR OR "POISON WEED". U. S. Dept. 

 Agr. Farmors' Bull. 088, rov., 13 pp., illns. 103-1. Supersedes Bull. 531. 



