Rrowly lanceolate, distinctly keeled, scabrous distally, keels to 1/2 and marginal veins to 1/3 short to long villous, intermediate veins and between veins usually RP54476MedChemExpress Dalfopristin sparsely softly puberulent, intermediate veins prominent, apices narrowly acute; paleas scabrous, glabrous over the keels. Flowers mainly cleistogamous; lodicules 0.6 mm long, lanceolate; anthers 0.3?.0 mm long. Caryopses 2 mm long, elliptical-fusiform in side-view, strongly laterally compressed, light brown, sulcus narrow, shallow, hilum 0.2 mm long, elliptical, grain adherent to the palea. 2n = 14, 28. Distribution. The species is known from Arizona, Colorado, New Mexico, and Texas, USA; and Coahuila, Mexico (Madera del Carmen). Ecology. The species occurs on slopes in wooded canyons with Pinus, Pseudotsuga, Cupressus, Abies, Ceanothus, Cornus stolonifera Michx., Bromus richardsonii Link, Festuca viridula Vasey, F. thurberi Vasey, and Quercus; ranging between 2280?550 m. Flowering August to September. Conservation status. The species is rare in Mexico. Specimens examined. Mexico. Coahuila: Madera del Carmen; canyon above Campo El Dos, 28?9’23.6″N, 102?6’43.0″W, 2280-2320 m, 8 Sep 2005, P.M.Peterson 18918 J.Valdes-Reyna (US; DNA voucher, unpublished). 13.8 mi NE of Los Pilares, 28?7’13.0″N, 102?5’7.3″W, 2335 m, 21 Sep 2007, P.M.Peterson 20979, J.M.Saarela, S.Lara-Contreras J.Reyna-Alvarez (US). 1.8 mi from Campo Uno, up the road towards the summit, 29?’14.2″N, 102?6’22.7″W, 2547 m, 23 Sep 2007, P.M.Peterson 21036 J.M.Saarela, S.Lara-Contreras J.Reyna-Alvarez (US). Discussion. This is the first report P. occidentalis for Mexico, and is a range extension of 460 km to the southeast. This species was previously known to occur from eastern Arizona (White Mountains) to southern Colorado, south through the mountains of New Mexico to the Guadalupe Mountains of Eddy County, Texas (Soreng 1985, 2007). Three new collections were gathered in northern Mexico in 2005 and 2007, in the upper coniferous forest belt of the Madera del Carmen, and these presumably represent a relictual population. The first glume of P. occidentalis was reported as 1-veined (Soreng ibid.), whereas it is principally 3-veined in the Mexican specimens, but re-examination of New Mexican specimens revealed this character state to vary from 1 to 3 veins. Poa occidentalis can be distinguished from other species Poa in Mexico by the following characters: its tall stature; short-lived perennial nature; long acute to acuminate, abaxially scabrous ligules that are longer than the leaf blades are wide; long and widely open, many spikeleted panicles; and anthers 0.5-1.0 mm long. Vasey (1893) considered his P. trivialis var. occidentalis published in 1885 to be “without description”, and taxonomists have traditionallyRobert J. Soreng Paul M. Peterson / PhytoKeys 15: 1?04 (2012)accepted this. However, in 1885, he provided an adequate diagnosis of his indigenous P. occidentalis var. occidentalis, from Colorado and New Mexico, by comparing it to the introduced P. trivialis L., which he described and noted had been established in the United States outside of cultivation (mainly in the eastern USA at low to moderate elevations). The Rocaglamide web isolectotypes indicate “July 1881”, and “Mts. near Las Vegas”, or “Mts. west of Las Vegas”, but there is no habitat “at Las Vegas” for the species, we presume all the material was collected in the mountains near or west of Las Vegas and to be of the same gathering as the lectotype. Vasey’s coll.Rrowly lanceolate, distinctly keeled, scabrous distally, keels to 1/2 and marginal veins to 1/3 short to long villous, intermediate veins and between veins usually sparsely softly puberulent, intermediate veins prominent, apices narrowly acute; paleas scabrous, glabrous over the keels. Flowers mainly cleistogamous; lodicules 0.6 mm long, lanceolate; anthers 0.3?.0 mm long. Caryopses 2 mm long, elliptical-fusiform in side-view, strongly laterally compressed, light brown, sulcus narrow, shallow, hilum 0.2 mm long, elliptical, grain adherent to the palea. 2n = 14, 28. Distribution. The species is known from Arizona, Colorado, New Mexico, and Texas, USA; and Coahuila, Mexico (Madera del Carmen). Ecology. The species occurs on slopes in wooded canyons with Pinus, Pseudotsuga, Cupressus, Abies, Ceanothus, Cornus stolonifera Michx., Bromus richardsonii Link, Festuca viridula Vasey, F. thurberi Vasey, and Quercus; ranging between 2280?550 m. Flowering August to September. Conservation status. The species is rare in Mexico. Specimens examined. Mexico. Coahuila: Madera del Carmen; canyon above Campo El Dos, 28?9’23.6″N, 102?6’43.0″W, 2280-2320 m, 8 Sep 2005, P.M.Peterson 18918 J.Valdes-Reyna (US; DNA voucher, unpublished). 13.8 mi NE of Los Pilares, 28?7’13.0″N, 102?5’7.3″W, 2335 m, 21 Sep 2007, P.M.Peterson 20979, J.M.Saarela, S.Lara-Contreras J.Reyna-Alvarez (US). 1.8 mi from Campo Uno, up the road towards the summit, 29?’14.2″N, 102?6’22.7″W, 2547 m, 23 Sep 2007, P.M.Peterson 21036 J.M.Saarela, S.Lara-Contreras J.Reyna-Alvarez (US). Discussion. This is the first report P. occidentalis for Mexico, and is a range extension of 460 km to the southeast. This species was previously known to occur from eastern Arizona (White Mountains) to southern Colorado, south through the mountains of New Mexico to the Guadalupe Mountains of Eddy County, Texas (Soreng 1985, 2007). Three new collections were gathered in northern Mexico in 2005 and 2007, in the upper coniferous forest belt of the Madera del Carmen, and these presumably represent a relictual population. The first glume of P. occidentalis was reported as 1-veined (Soreng ibid.), whereas it is principally 3-veined in the Mexican specimens, but re-examination of New Mexican specimens revealed this character state to vary from 1 to 3 veins. Poa occidentalis can be distinguished from other species Poa in Mexico by the following characters: its tall stature; short-lived perennial nature; long acute to acuminate, abaxially scabrous ligules that are longer than the leaf blades are wide; long and widely open, many spikeleted panicles; and anthers 0.5-1.0 mm long. Vasey (1893) considered his P. trivialis var. occidentalis published in 1885 to be “without description”, and taxonomists have traditionallyRobert J. Soreng Paul M. Peterson / PhytoKeys 15: 1?04 (2012)accepted this. However, in 1885, he provided an adequate diagnosis of his indigenous P. occidentalis var. occidentalis, from Colorado and New Mexico, by comparing it to the introduced P. trivialis L., which he described and noted had been established in the United States outside of cultivation (mainly in the eastern USA at low to moderate elevations). The isolectotypes indicate “July 1881”, and “Mts. near Las Vegas”, or “Mts. west of Las Vegas”, but there is no habitat “at Las Vegas” for the species, we presume all the material was collected in the mountains near or west of Las Vegas and to be of the same gathering as the lectotype. Vasey’s coll.
