Rydberg pentstemon, a perennial with blue or purple flowers and 

 opposite leaves, was named in honor of Dr. P. A. Rydberg (1860- 

 1931), an eminent Swedish-American taxonomic botanist, who con- 

 tributed greatly to the knowledge of western plants and was the 

 author of many publications on the flora of the West. Rydberg 

 pentstemon occurs in the mountains from Idaho to Montana, Colo- 

 rado, and Nevada, principally at elevations from 7,000 to 10,000 feet 

 and is common and often locally abundant, chiefly in the grass-weed, 

 sagebrush, arid aspen types. 



This species is one of the more palatable pentstemons and is fair 

 cattle and sheep forage. It reproduces by means of rootstocks and 

 is able to withstand considerable trampling and, because of these 

 facts and of the relatively light grazing to which it is ordinarily sub- 

 jected, it often increases on overgrazed ranges. Although not an 

 especially important range plant, this species has been selected for 

 illustration as representative of the large Pentstemon genus which, 

 chiefly because of its size, wide distribution, and abundance, consti- 

 tutes an important group of range weeds. 



PENTSTEMONS (Pentste'mon spp.) 



Pentstemons, composing a large, chiefly North American genus of 

 about 150 species, are perennial plants with opposite (or occasionally 

 whorled) leaves, and usually showy, often strongly two-lipped flow- 

 ers. The genus is best represented in the western United States 

 where the bulk of the species occur, constituting one of the common 

 floral elements of the great majority of the vegetative types from 

 sea level to the limits of plant growth, and often being locally 

 abundant. 1 The genus, belonging to the figwort family (Scrophu- 

 lariaceae), is one of the relatively few genera with five stamens in 

 that very large plant family; it is named rather appropriately, 

 Penkstemon being derived from the Greek pente, five, and stemon, 

 stamen. In most species only four stamens are anther-bearing, the 

 fifth one consisting only of the stalk (filament), which is usually 

 thickened toward the tip and frequently clothed with yellow hairs 

 (bearded) . However, in a few species the five stamens are all anther- 

 bearing and produce pollen. Pennell has stressed the point that 

 the original spelling of the generic name is Penstenwn^ and that 

 spelling is now accepted by some authors. 1 2 Some species are oc- 

 casionally known as foxglove or false-foxglove; those species in 

 which the sterile stamen is bearded are commonly called beardtongue. 



The pentstemons vary in palatability from practically worthless 

 to fairly good. Because of the great number and close relationship 

 of species of Pentstemon- most Forest officers and other observers, 

 other than professional botanists, fail frequently to distinguish the 

 species. As the species undoubtedly vary in palatability there has 

 arisen some confusion as to the palatability of these plants. Until 

 a thorough study can be made of the payabilities of individual 

 species of Pentstemon it is necessary to indicate the forage value of 



1 Dayton, W. A. IMPORTANT WESTERN BROWSE PLANTS. U. S. Dept. Agr. Misc. Pub. 

 101, 214 pp., illus. 1931. 



2 Pennell, P. W. SCROPHULARIACEAE OF THE CENTRAL ROCKY MOUNTAIN STATES. U. S. 

 Natl. Mus., Contrib. U. S. Natl. Herbarium 20:313-381. 1920. 



