Lemmon's Needlegrass: Achnatherum lemmonii ssp. lemmonii (Synonyms: Achnatherum lemmonii var. lemmonii, Eriocoma lemmonii ssp. lemmonii, Stipa columbiana, Stipa columbiana var. columbiana, Stipa lemmonii var. jonesii, Stipa lemmonii var. lemmonii)
Columbia Needlegrass, Dore's Needlegrass, Nelson's Needlegrass: Achnatherum nelsonii ssp. dorei (Synonyms: Eriocoma nelsonii ssp. dorei, Stipa nelsonii ssp. dorei, Stipa nelsonii var. dorei)
Columbia Needlegrass, Nelson's Needlegrass: Achnatherum nelsonii ssp. nelsonii (Synonyms: Eriocoma nelsonii ssp. nelsonii, Stipa columbiana var. nelsonii, Stipa nelsonii ssp. nelsonii, Stipa nelsonii var. nelsonii, Stipa occidentalis, Stipa occidentalis var. nelsonii, Stipa williamsii)
California Needlegrass: Achnatherum occidentale ssp. californicum (Synonyms: Achnatherum nelsonii ssp. longiaristatum, Stipa californica, Stipa nelsonii var. longiaristata, Stipa occidentalis var. californica)
Common Western Needlegrass, Western Needlegrass: Achnatherum occidentale ssp. pubescens (Synonyms: Eriocoma occidentalis ssp. pubescens, Stipa elmeri, Stipa occidentalis var. pubescens)
Thurber's Needlegrass, Thurber's Ricegrass: Achnatherum thurberianum (Synonyms: Eriocoma thurberiana, Stipa thurberiana)