title: An updated checklist and key to the open-panicled species of Poa L. (Poaceae) in Peru including three new species, Poa ramoniana, Poa tayacajaensis, and Poa urubambensis.
abstract: We provide an updated checklist and key to the 30 Poa species with open panicles from Peru which includes previously circumscribed Dissanthelium and Aphanelytrum species, new taxon records, and three undescribed species. Poa compressa, Poa grisebachii, and Poa leioclada are recorded from Peru for the first time. A number of species are placed in synonymy: Poa carazensis, Poa ferreyrae and Poa tovarii are synonymized under the name Poa fibrifera; Poa adusta (tentatively) and Poa pilgeri are synonymized under Poa candamoana; Poa superata is synonymized under Poa grisebachii; and Poa paramoensis is synonymized under Poa huancavelicae. Included within this treatment are three new species, Poa ramoniana, Poa tayacajaensis and Poa urubambensis, which are described and illustrated. Poa ramoniana, found growing near lakes in high elevation Puna grasslands of Junín, is similar to a small form of Poa glaberrima, but differs in having rhizomes and growing to only 5 cm tall. Poa tayacajaensis, found from shrublands on Andean slopes of Huancavelica and Huánuco, bears similarities to Poa aequatoriensis but differs in having shorter lemmas which are pubescent between the veins, densely scabrous sheaths with smooth, glabrous throats, and shorter ligules. Poa urubambensis, a common element of the undisturbed Polylepis forest understory of the Cordillera Urubamba, Cusco, is distinct from all other members of open-panicled Poa's by having glabrous lemmas with a smooth and glabrous callus, and notably small anthers. The type material for the name Poa adusta is discussed and a lectotype is selected.
authors.affiliation: Institute of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008 Zürich, Switzerland; Department of Geography, Philipps-Universität Marburg, Deutschhausstraße 10, D-35032 Marburg, Germany.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Sylvester
authors.affiliation: Department of Botany, National Museum of Natural History, Smithsonian Institution Washington, DC, 20013-7012, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Soreng
authors.affiliation: Department of Botany, National Museum of Natural History, Smithsonian Institution Washington, DC, 20013-7012, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Peterson
authors.affiliation: Institute of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008 Zürich, Switzerland; Universidad Nacional de San Antonio Abad del Cusco, Avenida de la Cultura 733, Cusco, Perú
authors.forename: Mitsy D P V
authors.initials: MD
authors.lastname: Sylvester
keywords: Checklist; Gramineae; Peru; Poa; Polylepis forest; Pooideae; Puna grassland; grass taxonomy; new species