The Genus Achnatherum East of the Cascade Mountains of Oregon and Washington

Bloomer's Ryegrass: Achnatherum xbloomeri (Synonyms: Oryzopsis bloomeri, Stipa bloomeri, Stiporyzopsis xbloomeri, Achnatherum hymenoides x occidentale)

Henderson's Needlegrass, Henderson's Ricegrass: Achnatherum hendersonii (Synonym: Oryzopsis hendersonii, Stipa hendersonii)

Indian Ricegrass: Achnatherum hymenoides (Synonyms: Eriocoma cuspidata, Oryzopsis cuspidata, Oryzopsis hymenoides, Stipa hymenoides)

Lemmon's Needlegrass: Achnatherum lemmonii ssp. lemmonii (Achnatherum lemmonii var. lemmonii, Stipa columbiana var. columbiana, Stipa lemmonii var. jonesii, Stipa lemmonii var. lemmonii)

Letterman's Needlegrass: Achnatherum lettermanii (Synonyms: Stipa lettermanii, Stipa minor, Stipa occidentalis var. minor)

Dore's Needlegras: Achnatherum nelsonii ssp. dorei (Synonyms: Stipa nelsonii var. dorei, Stipa nelsonii ssp. dorei)

Columbia Needlegrass, Nelson's Needlegrass: Achnatherum nelsonii ssp. nelsonii (Synonyms: Stipa columbiana var. nelsonii, Stipa nelsonii ssp. nelsonii, Stipa nelsonii var. nelsonii, Stipa occidentalis var. nelsonii, Stipa williamsii)

Nevada Needlegrass: Achnatherum nevadense (Synonym: Stipa nevadensis)

California Needlegrass: Achnatherum occidentale ssp. californicum (Synonyms: Stipa californica, Stipa nelsonii var. longiaristata, Stipa occidentalis var. californica)

Western Needlegrass: Achnatherum occidentale sp. occidentale (Synonym: Stipa occidentalis var. occidentalis)

Pubescent Western Needlegrass: Achnatherum occidentale ssp. pubescens (Synonyms: Stipa elmeri, Stipa occidentalis var. pubescens)

Pine Needlegrass: Achnatherum pinetorum (Synonym: Stipa pinetorum)

Richardson's Needlegrass: Achnatherum richardsonii (Synonym: Stipa richardsonii)

Desert Needlegrass: Achnatherum speciosum (Synonym: Stipa speciosa)

Thurber's Needlegrass: Achnatherum thurberianum (Synonym: Stipa thurberiana)

Wallowa Ricegrass: Achnatherum wallowaensis

Webber's Needlegrass: Achnatherum webberi (Synonyms: Oryzopsis webberi, Stipa webberi)

Needle and Thread: Hesperostipa comata (Synonym: Stipa comata)