Wn particularly for his work in southwestern USA and northern Mexico, who, in 1880, was the first to collect this plant. We selected the Pringle collection as type because it is widely distributed. Specimen examined. Mexico. Coahuila: mountains 6 mi east of Saltillo, Feb to Oct 1880, E.Palmer 1366 (GH, NY, US-924987). Sierra de Los Lirios, 2800 m, Jul to Aug 1942 [error for 1924?], E.Lyonnet 3691 (MEXU-379081, 379082). 22 km SE of San Antonio de las Alazanas, southeast of Saltillo, 20 Jul 1963, F.W.Gould 10538A D. Watson (TAES). Rinc de Mar , on Hacienda La Babia, ca. 70 road miles northwest from M quiz, 1750 m, 27 Apr 1975, T.Wendt 883 D.Riskind (LL). Cima de Sierra la Viga, ca. 3600 m, 24 Oct 1984, A.McDonald 1172 Gomez (TAES). ceja y ladera s de Sierra La Viga, 3700 m, 22 Aug 1986, A.McDonald 2104 (TEX, TEX). Las Vigas, Ca n de la BMS-986020 manufacturer Carbonera, Sierra de Arteaga, 2100-2600 m, 5 Jun 1987, J.A.Villarreal M.A.Carranza s.n. (MEXU-469611). Sierra La Marta, east of Cerro Moro, 3400 m, 22 Jul 1985, S.Ginzbarg 148, A.Whittemore A.McDonald (MEXU-666069). Sierra Coahuilon, ca. 3400-3500 m, 18 Jun 1985, A.McDonald 1485 M.H.Cervera (MEXU-1072101). SE of San Antonio de las Alazanas, SE of Saltillo, at end of road near Summit of Coahuilon, 25.2203 , 100.3305 , 3120 m, 17 Oct 1989, P.M.Peterson 8390, J.Valdes-Reyna, J.Villarreal (US-3518353). 51.6 km southeast of Saltillo and 13 km southeast of Jame on road to Sierra La Viga, 25.33 , 100.579 , 3240 m, 26 Sep 1990, P.M.Peterson 10053, C.R.Annable J.Valdes-Reyna (US). Sierra Zapalinam? east of Saltillo, 25.3468 , 100.9016 , 2700 m, 2 Sep 2005, P.M.Peterson 18787 J.Valdes-Reyna (US-3496160 (DNA voucher, unpublished, distributed as “P. ruprechtii”); ditto, E of Saltillo, “El Penitente”, 25.3468 , 100.9016 , 3070 m, 2 Sep 2005, P.M.Peterson 18790 J.Valdes-Reyna (US-3496160); ditto, along trail from El Cuatro to El Penitente, 25.3383 , 100.8882 , 2925 m, 28 Sep 2007, P.M.Peterson 21127, J.M.Saarela, S.G.G ez-P ez (US; DNA voucher, unpublished). Nuevo Le : Cerro Potos? east slope, 2135 m, 9 Jul 1963, R.L.McGregor 385, L.J.Harms, A.J.Robinson, R.delRosario, R.Segal (US-2454930).Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: …Discussion. A provisional key to 11 species of Poa in northern Mexico (excluding Baja California) is GDC-0084 chemical information provided in Peterson et al. (2006). In that paper we concluded that P. ruprechtii, as widely applied, was heterogeneous. However, until we could examine the type of P. ruprechtii (C. Heller 312) we could not be sure of the application of the name. Here we emend the description of P. ruprechtii Peyr. s.s., and treat the material of northeastern Mexico as a new species. Poa palmeri has long been confused with P. ruprechtii (Fournier 1886, Hitchcock 1913, Beetle et al. 1999, Espejo Serna et al. 2000, D ila Aranda et al. 2006). Poa palmeri differs in several leaf, panicle, and spikelet characters, and has longer anthers, and the two species do not overlap in geographic range. There is a note on Palmer’s label at US, “Poa ruprechtii Peyr, so named at Kew, S.W. (RJS-presumably Sereno Watson), but scarcely distinct from P. flexuosa Muhl.” (= Poa autumnalis Muhl. ex Elliott of lowlands from the central and southern Appalachians), and a further note; “related to P. flexuosa” apparently written by A.S. Hitchcock. Interestingly, this name was also applied to the type of Poa ruprechtii at W (Fig. 16). This presumably stems from Peyritsch’s final statement (p.Wn particularly for his work in southwestern USA and northern Mexico, who, in 1880, was the first to collect this plant. We selected the Pringle collection as type because it is widely distributed. Specimen examined. Mexico. Coahuila: mountains 6 mi east of Saltillo, Feb to Oct 1880, E.Palmer 1366 (GH, NY, US-924987). Sierra de Los Lirios, 2800 m, Jul to Aug 1942 [error for 1924?], E.Lyonnet 3691 (MEXU-379081, 379082). 22 km SE of San Antonio de las Alazanas, southeast of Saltillo, 20 Jul 1963, F.W.Gould 10538A D. Watson (TAES). Rinc de Mar , on Hacienda La Babia, ca. 70 road miles northwest from M quiz, 1750 m, 27 Apr 1975, T.Wendt 883 D.Riskind (LL). Cima de Sierra la Viga, ca. 3600 m, 24 Oct 1984, A.McDonald 1172 Gomez (TAES). ceja y ladera s de Sierra La Viga, 3700 m, 22 Aug 1986, A.McDonald 2104 (TEX, TEX). Las Vigas, Ca n de la Carbonera, Sierra de Arteaga, 2100-2600 m, 5 Jun 1987, J.A.Villarreal M.A.Carranza s.n. (MEXU-469611). Sierra La Marta, east of Cerro Moro, 3400 m, 22 Jul 1985, S.Ginzbarg 148, A.Whittemore A.McDonald (MEXU-666069). Sierra Coahuilon, ca. 3400-3500 m, 18 Jun 1985, A.McDonald 1485 M.H.Cervera (MEXU-1072101). SE of San Antonio de las Alazanas, SE of Saltillo, at end of road near Summit of Coahuilon, 25.2203 , 100.3305 , 3120 m, 17 Oct 1989, P.M.Peterson 8390, J.Valdes-Reyna, J.Villarreal (US-3518353). 51.6 km southeast of Saltillo and 13 km southeast of Jame on road to Sierra La Viga, 25.33 , 100.579 , 3240 m, 26 Sep 1990, P.M.Peterson 10053, C.R.Annable J.Valdes-Reyna (US). Sierra Zapalinam? east of Saltillo, 25.3468 , 100.9016 , 2700 m, 2 Sep 2005, P.M.Peterson 18787 J.Valdes-Reyna (US-3496160 (DNA voucher, unpublished, distributed as “P. ruprechtii”); ditto, E of Saltillo, “El Penitente”, 25.3468 , 100.9016 , 3070 m, 2 Sep 2005, P.M.Peterson 18790 J.Valdes-Reyna (US-3496160); ditto, along trail from El Cuatro to El Penitente, 25.3383 , 100.8882 , 2925 m, 28 Sep 2007, P.M.Peterson 21127, J.M.Saarela, S.G.G ez-P ez (US; DNA voucher, unpublished). Nuevo Le : Cerro Potos? east slope, 2135 m, 9 Jul 1963, R.L.McGregor 385, L.J.Harms, A.J.Robinson, R.delRosario, R.Segal (US-2454930).Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: …Discussion. A provisional key to 11 species of Poa in northern Mexico (excluding Baja California) is provided in Peterson et al. (2006). In that paper we concluded that P. ruprechtii, as widely applied, was heterogeneous. However, until we could examine the type of P. ruprechtii (C. Heller 312) we could not be sure of the application of the name. Here we emend the description of P. ruprechtii Peyr. s.s., and treat the material of northeastern Mexico as a new species. Poa palmeri has long been confused with P. ruprechtii (Fournier 1886, Hitchcock 1913, Beetle et al. 1999, Espejo Serna et al. 2000, D ila Aranda et al. 2006). Poa palmeri differs in several leaf, panicle, and spikelet characters, and has longer anthers, and the two species do not overlap in geographic range. There is a note on Palmer’s label at US, “Poa ruprechtii Peyr, so named at Kew, S.W. (RJS-presumably Sereno Watson), but scarcely distinct from P. flexuosa Muhl.” (= Poa autumnalis Muhl. ex Elliott of lowlands from the central and southern Appalachians), and a further note; “related to P. flexuosa” apparently written by A.S. Hitchcock. Interestingly, this name was also applied to the type of Poa ruprechtii at W (Fig. 16). This presumably stems from Peyritsch’s final statement (p.