1. Family: Poaceae Barnhart
    1. Genus: Poa L.
      1. Poa arida Vasey

        This species is accepted, and its native range is Canada to N. & Central U.S.A.

    [GB]
    Habit
    Perennial; caespitose. Rhizomes elongated. Butt sheaths herbaceous. Culms 15-80 cm long. Culm-internodes terete; striate; smooth, or scaberulous. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths with 0.2 of their length closed; glabrous on surface. Ligule an eciliate membrane; 1-4 mm long; entire, or lacerate; acute. Leaf-blades flat, or conduplicate; 3-12 cm long; 1-5 mm wide; 1-6 cm long at summit of culm; light green, or glaucous. Leaf-blade surface glabrous.
    Inflorescences
    Inflorescence a panicle. Panicle open; lanceolate; 4-12 cm long. Primary panicle branches appressed; 2-3 -nate. Panicle branches scabrous. Spikelets solitary. Fertile spikelets pedicelled.
    Spikelets
    Spikelets comprising 3-7 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 4-7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth; pubescent. Floret callus glabrous.
    Fertile
    Spikelets comprising 3-7 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 4-7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth; pubescent. Floret callus glabrous.
    Glume
    Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 2.5-3.5 mm long; 0.9 length of upper glume; membranous; 1-keeled. Lower glume primary vein smooth, or scaberulous. Lower glume apex acute. Upper glume oblong; 2.5-4 mm long; 0.66-0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein smooth, or scaberulous. Upper glume apex acute.
    Florets
    Fertile lemma oblong; oblong in profile; 2.5-4 mm long; membranous; keeled; lightly keeled; 5 -veined. Lemma midvein ciliolate; hairy below. Lemma lateral veins prominent. Lemma surface glabrous, or pilose; hairy below. Lemma margins ciliolate; hairy below. Lemma apex obtuse, or acute. Palea 0.9 length of lemma. Palea keels ciliolate, or ciliate. Apical sterile florets resembling fertile though underdeveloped.
    Flowers
    Lodicules 2; membranous. Anthers 3; 1.3-1.7 mm long.
    Fruits
    Caryopsis with adherent pericarp. Hilum punctiform.
    Distribution
    North America: western Canada, northwest USA, north-central USA, southwest USA, and south-central USA.
    Reference
    Poeae. Soreng 1992.

    Images

    Distribution

    Native to:

    Alberta, Colorado, Illinois, Indiana, Iowa, Kansas, Manitoba, Michigan, Minnesota, Montana, Nebraska, New Mexico, North Dakota, Ohio, Oklahoma, Ontario, Québec, Saskatchewan, South Dakota, Texas, Wyoming

    Poa arida Vasey appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Nuttall [s.n.], USA K000633958
    Vasey, G.R. [s.n.], New Mexico K000633957

    First published in Contr. U.S. Natl. Herb. 1: 270 (1893)

    Accepted by

    • Flora of North America Editorial Committee (2007). Flora of North America North of Mexico 24: 1-908. Oxford University Press, New York, Oxford.
    • Clayton, W.D., Harman, K.T. & Williamson, H. (2006). World Grass Species - Synonymy database The Board of Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Kew Backbone Distributions
    • Flora of North America Editorial Committee (2007). Flora of North America North of Mexico 24: 1-908. Oxford University Press, New York, Oxford.

    Sources

    GrassBase - The Online World Grass Flora
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0