The squirreltails, Elymus elymoides (Raf.) Swezey (bottlebrush squirreltail) (Poaceae) and E. multisetus (J.G. Smith) Burtt Davy (big squirreltail), occupy rangelands in the arid and semiarid portions of the northwestern US. Bottlebrush squirreltail exhibits multiple subspecies, while big squirreltail does not. Commercially available plant materials of squirreltail have been keyed and are listed by their taxon. A dichotomous key is presented to identify the correct squirreltail taxon that is based on the number of glumes per node and the cleavage displayed by those glumes. This key was developed from a previous key published in 1963 that was based on a now-obsolete systematic treatment. The new key better reflects phylogenetic relationships, as it is based on Dewey’s genomic system of classification rather than on morphological characters.
. A nomenclatural guide and simplified key to the squirreltail taxa. Native Plants Journal 15(1):51–55.