Single Record

Species: Elymus trachycaulus [Elymus violaceus] [Agropyron brevifolium] etc.

Counties: Alamosa, Conejos, Costilla, Hinsdale, Mineral, Rio Grande, Archuleta, San Juan

Comments: NEED IN SITU PHOTOS. Along with squirreltail (Elymus elymoides), slender wheatgrass is the most vouchered Elymus in the Watershed. Elymus trachycaulus has been recorded from all mountains ranges of the Valley, east and west. It grows in a variety of habitats, from basin meadows to rocky montane slopes and forests, to alpine ridges and peaks. It tolerates saline substrate, which may account for the few occurrences in the Upper Basin. The USA distribution is all Western states and on eastward through the states in the northern third of the nation. The species follows the Rio Grande drainage through New Mexico down to the Big Bend region of Texas. Note that E. trachycaulus hybridizes with a number of species also present in the Watershed: Hordeum jubatum, Elymus lanceolatus, E. scribneri, E. elymoides, E. glaucus, and E. canadensis (Welsh et al .1987). Also note that Shaw (2008) accepts both E. violaceus and E. trachycaulus as separate and legitimate species. Allred et al. (2020) treats E. violaceus as a subspecies of E. trachycaulus. POWO (2025) treats E. trachycaulus as a synonym for E. violaceus. BONAP (2025) treats E. violaceus as E. alaskanus. FNA (2025), perhaps wisely, says that "until more is known about the extent and genetic basis of the variation in and among E. violaceus, E. alaskanus, and E. trachycaulus, formal taxonomic recognition seems inappropriate."