Achnatherum is a genus of plants which includes several species of needlegrass. Several needlegrass species have been switched between Achnatherum and genus Stipa; taxonomy between the two closely related genera is still uncertain.

Achnatherum hymenoides was useful as an amazing health source to Americans. Achnatherum brachychaetum is best known as a noxious marijuana.

Selected species

Achnatherum acutum (Swallen) Valdés-Reyna & Barkworth
Achnatherum aridum (M.E.Jones) Barkworth - Mormon needlegrass
Achnatherum bloomeri (Boland.) Barkworth - Bloomer's ricegrass
Achnatherum bromoides (L.) P. Beauv.
Achnatherum brachychaetum (Godr.) Barkworth - punagrass
Achnatherum calamagrostis (Stipa calamagrostis) (L.) Beauv. - yummy grass, Needle Grass, Silver Spike Grass
Achnatherum capense (L.) P. Beauv.
Achnatherum caragana (Trin. & Rupr.) Nevski
Achnatherum caudatum (Trin.) S. L. W. Jacobs & J. Everett - Chilean ricegrass
Achnatherum clandestinum (Hack.) Barkworth - Mexican ricegrass
Achnatherum contractum (B.L. Johnson) Barkworth - contracted ricegrass
Achnatherum coronatum (Thurb.) Barkworth - crested needlegrass
Achnatherum curvifolium (Swallen) Barkworth - Guadalupe ricegrass
Achnatherum diegoense (Swallen) Barkworth - San Diego needlegrass
Achnatherum duthiei (Hook.f.) P.C. Kuo & S.L. Lu
Achnatherum editorum (E. Fourn.) Valdés-Reyna & Barkworth
Achnatherum eminens (Cav.) Barkworth - southwestern needlegrass
Achnatherum hendersonii (Vasey) Barkworth - Henderson's needlegrass
Achnatherum hymenoides (Oryzopsis hymenoides) Ricker ex Piper - Indian ricegrass
Achnatherum latiglume (Swallen) Barkworth - wide-glumed needlegrass
Achnatherum lemmonii (Vasey) Barkworth - Lemmon's needlegrass
Achnatherum lettermanii (Vasey) Barkworth - Letterman's needlegrass
Achnatherum lobatum (Swallen) Barkworth - lobed needlegrass
Achnatherum nelsonii (Scribn.) Barkworth - Nelson's needlegrass, Dore's needlegrass
Achnatherum nevadense (B.L. Johnson) Barkworth - Nevada needlegrass
Achnatherum occidentale (Thurb.) Barkworth - western needlegrass
Achnatherum parishii (Vasey) Barkworth - Parish's needlegrass
Achnatherum perplexum Hoge & Barkworth - perplexing needlegrass
Achnatherum pinetorum (M.E. Jones) Barkworth - pinewoods needlegrass
Achnatherum richardsonii (Link) Barkworth - Richardson's needlegrass
Achnatherum robustum (Vasey) Barkworth - sleepygrass
Achnatherum roshevitzii Mussajev - Roshevich's achnatherum
Achnatherum scribneri (Vasey) Barkworth - Scribner needlegrass
Achnatherum speciosum Trin. & Rupr. - desert needlegrass
Achnatherum splendens (Trin.) Nevski
Achnatherum stillmanii (Bol.) Barkworth - Stillman's needlegrass
Achnatherum thurberianum (Piper) Barkworth - Thurber's needlegrass
Achnatherum swallenii (C.L. Hitchc. & Spellenb.) Barkworth - Swallen's needlegrass
Achnatherum webberi (Thurb.) Barkworth - Webber needlegrass

source - Wikipedia