The boundaries of Achnatherum are not clear. Tsvelev (1976) described it as a genus of 15-20 species native to marginally warm and subtropical regions of Eurasia, North Africa, and North America. A year later (1977), he was persuaded by Keng to expand the genus to include several additional species with a blunt callus. Thomasson () demonstrated that the transferred species were similar in several respects, but particularly their lemma epidermal pattern, to many North American species. Subsequently Barkworth (1993) formally transferred the species to Achnatherum, along with some South American taxa.  She has since concluded that there are no South American species of Achnatherum.

Until the limits of the genus are better understood, it is difficult to provide a generic description of Achnatherum. Its recent interpretation is, in many respects, a negative one - it comprises species that used to be included in Stipa but from which the type of Stipa (and its relatives) is excluded. 

The type of Achnatherum is A. calamagrostis Beauv. 

Table of Taxa (very incomplete)

The information in the table below, like that in other tables, has been compiled from a number of different sources but, in many instances, the generic treatment has been modified to reflect my narrow interpretation of Stipa and relatively broad interpretation of Achnatherum. Because not all taxa that I would include in Achnatherum have names under that genus, many taxa are listed as species of Stipa. I have also shown the name in Stipa for many species, as an aid to those that do not accept Achnatherum in its broad sense.

Sources: Freitag 1985 [Maps]; Vázquez and Devesa (1996); Flora of China (2006).





  Achnatherum sect. Aristella (Trin.) Tzvelev Stipa a. aristella Trinius; Aristella (Trin.) Bertol.; S. sect. Aristella (Trinius) Hackel;Stipa subg. Aristella (Trin.) Rouy; Stipa ser. Bromoides Martinovsky; S. sect. Leiostipa ser. Bromoides (Martinovsky) Moraldo  
1 Achnatherum aridum   U.S.A. (western)
2 Achnatherum brandisii (Mez) Z.L. Wu   Afghanistan, Bhutan, China (Gansu, Winghai, Sichuan, Xizang, Yunnan), India, Nepal, Pakistan
3 Achnatherum breviaristatum Keng & P.C. Kuo   China (Gansu)
4 Achnatherum bromoides (L.) Beauv.

Agrostis bromoides L.; Aristella bromoides (L.) Bertol.; Achnatherum bromoides (L.) Beauv; Stipa bromoides (L.) Dörfler; Lasiagrostis (L.) Nevski; Stipa aristella L. Africa (north); Azerbaijan; Cyprus; Iran; Iraq; Israel; Palestine Spain; Syria; Turkey

S. Aegean Islands

5 Achnatherum calamagrostis (L.) Beauv.


Agrostis calamagrostis L.; Stipa calamagrostis (L.) Wahlenb.; Lasiagrostis calamagrostis (L.) Link Europe (South, central south); Spain (northern)

Achnatherum capense

Questionably in Achnatherum

S. (Stipella) capensis Thunb.; S. retorta Cavanilles; S. tortilis Desfontaines Mediterranean, naturalized in Macronesia, southern Africa. Afghanistan; Cyprus; Egypt; Iran; Iraq; Jordan; Pakistan; Palestine; Saudi Arabia; Syria; Turkey
7 Achnatherum caragana (Trinius) Nevski  S. (Lasiagrostis) caragana Trinius; Lasiagrstis caragana (Trin.) Trinius & Ruprehct; Oryzopsis pallescens Westberg; O. asiatica Mez Afghanistan; CAUCASUS, China (Xingjiang), Iran; Kazakhstan, Pakistan; Russia, Tajikistan, Turkey
8 Achnatherum chinense (Hitchc.) Tzvelev   China (Gansu, Hebei, Henan, Nei Mongol, Nigxia, Qinghai, Shaanxi, Shanxi)
9 Achnatherum chingii (Hitchc.) Keng ex P.C. Kuo   China (Gansu, Qinghai, Shaanxi, Shanxi, Sichuan, Xizang, Yunnan)
10 Achnatherum coreanum (Honda) Ohwi Stipa coreana

China (Anhui, Hebei, Hubei, Jiangsu, Jiangxi, Shaanxi, Zhejiang), Korea, Japan.

Has hairy ovary

11 Achnatherum coronatum (Thurber) Barkworth Stipa coronata Thurber U.S.A. and Mexico: Southwestern California and adjacent Mexico
12 Achnatherum contractum
(B.L. Johnson) Barkworth
Oryzopsis contracta (B.L. Johnson) Shechter U.S.A.: Wyoming
Fertile hybrid between Achnatherum and Piptatherum? See Shechter & Johnson 1966, 1968; Shechter 1969
13 Achnatherum curvifolium   U.S.A. (southwestern)
14 Achnatherum diegoense   Mexico, U.S.A.
15 Achnatherum duthei (Hook.) P.C. Kuo & S.L. Luo   China (Qinhai, Shaanxi, Sichuan, Xizang, Yunnan), India (Sikkim), Kashmir, Nepal
16 Achnatherum editorum (Fourn.) Valdes-Reyna Stipa editorum Fourn. Central Mexico
17 Achnatherum eminens (Cav.) Barkworth Stipa eminens Cav. Southwestern U.S.A. and Mexico
18 Achnatherum hendersonii (Vasey) Barkworth Oryzopsis hendersonii Vasey Northwestern contiguous U.S. Rare species
19 A. henryi (Rendle) S.M. Phillips & Z.L. Wu    
    var. acutum   China (Yunnan)
    var. henryi   China (Gansu, Hubei, Shaanxi, Sichuan, )
20 Achnatherum hymenoides (Roem. & Schult.) Barkworth Oryzopsis hymenoides (Roem. & Schult.) Ricker; Stipa hymenoides Roem. & Schult. Widespread western North American species
21 Achnatherum inaequiglume Keng & P.C. Kuo   China (Gansu, Sichuan)
22 Achnatherum inebrians (Hance) Keng Stipa inebrians Hance China (Gansu, Nei Mongol, Nigxia, Qinghai,, Sichuan, Xinjiang, Xizang), Mongolia
23 Achnatherum jacquemontii (Jaub. & Spach) P.C. Kuo & S.L. Lu   Afghanistan, China (Xizang), India, Kashmir, Pakistan
24 Achnatherum latiglume   U.S.A. (California)
25 Achnatherum lemmonii (Vasey) Barkworth Stipa lemmonii Vasey Western Canada and U.S.A.
26 Achnatherum lettermanii   U.S.A.
27 Achnatherum lobatum (Swallen) Barkworth Stipa lobata Swallen U.S.A. and Mexico: southern Arizona, New Mexico, west Texas and northcentral Mexico. 
28 Achnatherum longearistatum (Boissier) Nevski  S. (Aristella) kurdistanica Bor; Pipthatherum longearistatum Boiss. & Hausskn. ex Boissier; Oryzopsis longearistata (Boissier) Roshevits; Lasiagrostis longearistata (Boissier) Roshevits & Nevski ex Roshevits; Iran and Iraq (Zagros Mountains)
29 Achnatherum nakai (Honda) Taeoka ex Imzab   China (Hebei, Liaoning, Nei Mongol, Shanxi), Mongolia
30 Achnatherum nelsonii (Scribner) Barkworth Stipa nelsonii Scribn. Western North America
31 Achnatherum nevadense   U.S.A. (western)
32 Achnatherum occidentale   U.S.A. (western)
33 par   U.S.A.

Stipa parviflora Desf.


  France (southern), Spain, Morocco, Algeria
35 Achnatherum pekinense (Hance) Ohwi   China (Anhui, Gansu, Hebei, Heilongjiang, Henan, Jilin, Nei Mongoal, Ningxia, Shaanxi, Shandong, Shanxi, Yunnan), Japan, Korea, Russia
36 Achnatherum perplexum Hoge & Barkworth   Southwestern U.S.A.
37 Achnatherum pinetorum (M.E. Jones) Barkworth Stipa pinetorum Western (but interior)  U.S.A
38 Achnatherum psilantherum Keng exTzvelev   China (Gansu, Qinqhai, Sichuan)
39 Achnatherum pubicalyx (Ohwi) Keng ex P.C. Kuo   China (Gansu, Hebei, Heilongjiang, Jilin, Nei Mongol, Qinghai, Shaanxi, Xinjiang), Korea
40 Achnatherum richardsonii   Canada, U.S.A.
41 Achnatherum robustum (Vasey) Barkworth Stipa robusta Vasey western U.S.A.
42 Achnatherum saposhnikovii (Roshevitz) Nevski   China (Gansu, Neil Mongol, Nigxia, Qinghai, Xinjiang), Kazackhstan, Kyrgyzstan, Mongolia, Uzbekistan
43 Achnatherum scribneri   U.S.A. (Colorado, Utah)
44 Achnatherum sibiricum (L.) Keng Stipa sibirica L. CAUCASUS, China (Heilongjiang, Henan, Nei MOngol, Ningxia, Qinghai, Sichuan, Xinjiang, Yunnan), Kazakhstan, Kyrgyrstan, Mongolia, Russia, uzbekistan, Caucasus
45 Achnatherum speciosum (Trin. & Rupr.) Barkworth Stipa speciosa Trin. & Rupr.

This generic disposition is in serious question. Other suggestions are Jarava or in a promoted Stipa subg. Pappostipa to a genus. 

Chile, Argentina and, as a disjunct, western U.S.A.
46 Achnatherum splendens (Trinius) Nevski Stipa splendens Trinius; Lasiagrostis splendens (Trinius) Kunth; S. altaica Trinius; Aristella longiflora Regel; S. schlagintweitii Mez; S. kokonorica Hao; S. munroana Bor Afghanistan, China (Gandu, Heilongjiang, Henan, Nei Mongol, Ningxia, Qinghai, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan), India, Kyrgyzstan, Mongolia, Pakistan, Russia (southern Urals, lower Volga, Siberia) Tajikistan, Turkmenistan, Uzbekistan.  

Achnatherum stillmanii

Placement in Achnatherum dubious, better than in Stipa.

48 Achnatherum swallenii   U.S.A. (western)
49 Achnatherum thurberianum   U.S.A. (western)
50 Achnatherum turcomanicum (Roshevits) Tzvelev S. litwinowiana Smirnow ex Pavlov & Lipsch.; Lasiagrostis litwinowiana Smirnow ex Gamajun et al.; Oryzopsis turcomanica Roshevits; Afghanistan; Iran (north); Kazakhstan; Turkmenia (south)
51 Achnatherum wallowaense   U.S.A.
52 Achnatherum webberi   U.S.A. (western)