Rocky Mountain sweetvetch is a perennial herb of the pea family and super- 

 ficially resembles certain locos, peavines, and vetches. It has a stout, tough, 

 deep taproot and a somewhat woody root crown from which grow several fairly 

 leafy, branching stems from 6 to 30 inches long. Some of the stems are rather 

 erect and others extend out laterally along or near the ground a few inches 

 before curving upward. 



The name Hedj/sarum is from the two Greek words hedys (sweet) and 

 aroma (a spice or sweet herb; whence our English word aroma, meaning 

 pleasant odor) apparently referring to the fragrant flowers and sweet-tasting 

 herbage of some species. "Joiutpod" is sometimes applied as a common name, 

 because of the peculiar jointed pods (loments). Depending on the species con- 

 cept of the individual botanist, about 9 to 11 species of sweetvetch occur in the 

 West, ranging from Alaska to the Dakotas, New Mexico, Nevada, and Oregon. 

 The genus apparently does not occur in California and Arizona. 



Rocky Mountain sweetvetch is one of the most widespread and abundant of 

 these species and is selected here as illustrative and characteristic of the genus 

 Hedysarum from a range standpoint. It ranges from Montana to Utah and 

 New Mexico and is the only species of Hedysarum occurring in New Mexico. 

 Generally, it is scattered sparsely but is limitedly abundant on a few localized 

 areas. Rocky Mountain sweetvetch grows mostly on dry, open, or lightly 

 shaded areas in the sagebrush, oakbrush, ponderosa pine, and aspen belts at 

 elevations from 4,000 to 10,000 feet. 



Some observers have reported Rocky Mountain sweetvetch to be of low 

 palatability, but almost certainly they have confused it with loco. Of course, 

 the association of sweetvetch with abundant and very choice grasses will 

 doubtless reduce its consumption by livestock. It is of interest to note that 

 Prof. Aven Nelson, in describing this species, 1 states that it "is reputed an 

 excellent forage plant", and the scientific name he applied to the species (pa&- 

 ulare) 2 reflects this viewpoint. Moreover, this appears to be the species which 

 Prof. Nelson formerly called "H. mackenzii" and which he states is greatly 

 relished by livestock, of frequent occurrence, locally abundant, and an im- 

 portant source of forage in the Red Desert of Wyoming. 3 



Utah sweetvetch (H. utahen'se) is very similar to Rocky Mountain sweet- 

 vetch, very closely related to it, and probably intergrades with it. Hedysarum 

 utahense differs chiefly in its flowers, which are more rose-purple and have 

 a little longer calyx. Utah sweetvetch is limited to Utah and eastern Idaho, 

 but is there locally abundant. Forest Service technicians report it as mod- 

 erately to well used on Utah ranges, by both sheep and cattle, although in- 

 tensive use of the species is related to close grazing of the range. Artificial 

 reseeding trials made with Utah sweetvetch in its native habitat by the Inter- 

 mountain Forest and Range Experiment Station have thus far failed. 



Sweetvetch species, as a rule, are grazed by all classes of domestic live- 

 stock. Their strong, woody, deep taproots get sustenance from a large soil 

 area and render the plants resistant to abuse. The peculiar, easily broken, 

 jointed pods are conducive to seed dispersal, on which reproduction of the 

 plants is necessarily dependent. Reports of these plants holding their own, 

 or even increasing, on overgrazed range are doubtless correlated, in part, with 

 these root and fruit characters, and probably also with less resistant qualities 

 of associated palatable species. The plants are frequently confused with loco- 

 weeds by observers, hut the gland-dotted leaves (apparent when held to the 

 light), the squared effect of the flower tips, and above all the characteristic 

 pods clearly distinguish Hedysarum from Astragalus. 



In parts of southern Italy, Algeria, Spain, and other portions of the Medi- 

 terranean region a native species of sweetvetch called "sulla" (H. coronarium) 

 is a very important cultivated forage plant, locally having about the same 

 status as alfalfa does in this country, 



1 Nelson, A. THE GENUS HEDYSAKUM IN THE ROCKY MOUNTAINS. Biol. Soc. Wash. 

 Proc. 15 : 183-186. 1902. 



2 Latin pabularis, -c, fit for fodder (pabulum). 



8 Nelson, A. THE RED DESERT OP WYOMING AND ITS FORAGE RESOURCES. U. S. Dept. 

 Agr., Div. Agrost. Bull. 13, 72 pp., illus. 1898. 



