This erect, leafy shrub or small tree, which attains a height of 30 

 feet or more, as well as the similar and closely related black choke- 

 cherry (P. melamooar' pa) are rather common on the western ranges. 

 Unfortunately, there is a diversity of opinion among botanists as to 

 the scientific name which should be applied to these two chokecherries. 

 Two eminent American dendrologists have considered both P. demissa 

 and P. melanoccarpa, as varieties of the common chokecherry (P. vir- 

 giniana) of the eastern United States. Western botanists, however, 

 do not agree; some authorities give both demissa and melanocarpa 

 specific rank; others, composed largely of Pacific coast botanists, 

 recognize P. demissa as a valid species and relegate P. melanocarpa 

 to varietal rank or suppress it altogether. From a taxonornic stand- 

 point, it is probably preferable to adhere to present usage in the 

 United States Department of Agriculture and recognize both 

 P. demissa and P. melanocarpa as very closely related, but distinct, 

 species. However, for range-management purposes, they may well 

 be considered identical, because of analogous habits and characters, 

 and similarity in forage value. 



Western chokecherry occurs from British Columbia to western 

 Montana and California. Black chokecherry is more midely dis- 

 tributed, occurring in the plains, valleys, and mountains from 

 British Columbia to North Dakota, Kansas, New Mexico, and Cali- 

 fornia. The elevational range is from near sea level at their north- 

 ern limits and (for black chokecherry) 2,000 feet in the plains east 

 of the Kockies to (for black chokecherry) about 9,000 feet in the 

 mountains of Colorado. These woody plants are generally most 

 abundant from the foothills to the ponderosa-pine belt of the moun- 

 tains. They grow in sunny, moist, or relatively dry situations, the 

 largest specimens usually being associated with willows, alders ; 

 aspen, and dogwood along the streams in open valleys or in sparsely 

 timbered, warm and sunny canyons. They also grow about springs, 

 seeps, and other moist places, but pure and brushy stands are largely 

 limited to moist or well-drained, warm slopes or sandy flats. They 

 usually occur on deep, rather fertile, sandy soils, but frequently do 

 well on rocky talus slopes and about rim rocks. 



Although poisonous under some conditions, 1 these two choke- 

 cherries are often grazed moderately and in combination with other 

 forage without ill effect. Fortunately, they are not of high palata- 

 bility, the leaves, twigs, and green bark having a bitter flavor, which 

 is not entirely agreeable to livestock. On the open range they rate 

 as poor to fair forage for both cattle and sheep; and, although 

 losses sometimes occur ? they usually are attributable to abnormal 

 use of these chokecherries, as a result of overgrazing or other causes. 

 Most fatalities due to eating these plants occur in areas where live- 

 stock are concentrated, such as about water, in corrals and pastures, 

 and along driveways or near bedgrounds. 



The active principle in western chokecherry and black chokecherry, 

 as well as in the closely related common chokecherry of the East, 

 which causes poisoning, is hydrocyanic (prussic) acid (HCN). 

 Strange to say, this acid is not present in the green and healthy 



1 Marsh, C. D. STOCK-POISONING PLANTS OF THE RANUE. U. S. Dept. Agr. Bull. 1245, 

 rev., 75 pp., illus. 1929. Supersedes Bull. 575. 



