256 PRINCIPAL STOCK-POISONING PLANTS 



unsatisfactory, and the genus is much in need of revision tax- 

 onomically. The larkspur species of the western ranges, how- 

 ever, may conveniently be divided into two general groups — 

 tall larkspur (Fig. 85, colored plate) and low larkspur (Fig. 

 86, colored plate). These two groups differ somewhat in their 

 choice of growth sites. The tall species prefer the moist, shel- 

 tered gulches and canyons of the higher ranges. Delphinium 

 Barbeyi is the representative tall larkspur species of Colorado, 

 and is also found in the mountains of Wyoming, Montana, and 

 Utah. It grows at altitudes of about 8,000 feet to approxi- 

 mately timberline. The most common species in Montana is 

 D. cucullatum, which is the cause of most of the losses of cattle 

 on mountain ranges in that State. 



Low larkspur grows on open hillsides, in drier localities than 

 the tall species, and at somewhat lower elevations. Typical 

 of the low species are D. Menziesii, which grows at elevations 

 of from 4,000 to 10,000 feet, and sometimes spreads over large 

 tracts, and D. bicolor, which grows at lower altitudes than D. 

 Menziesii and is not so abundant. These species are more or 

 less poisonous to cattle until after the seeds fall. 



Both tall and low larkspurs are common in Wyoming, Colo- 

 rado, Utah, Montana, and New Mexico, and are found in vary- 

 ing abundance in the foothill and mountain pastures over the 

 greater part of the West. 



Losses of Stock and Animals Poisoned. — It is probable 

 that more deaths among cattle on western ranges are caused by 

 larkspur than by any other poisonous plant. Serious cases of 

 loss of cattle from this cause are on record. For example, one 

 report states that 35 out of a herd of 500 cattle died within five 

 hours; in another herd 200 out of 3,000 died; and in another, 

 200 out of a herd of 5,000.^ The estimated money loss of cattle 

 from this cause on the Fishlake National Forest ranges in Utah 

 in 1915 was $15,000. 



So far as observations and experiments show, sheep are never 

 poisoned by larkspur; on the contrary, the plants are considered 



1 Marsh, C. D., and Clawson, A. B., "Larkspur Poisoning of Livestock." U. S. 

 Dept. of Agr. Bui. 365, p. 12, 1916. 



