1. Family: Poaceae Barnhart
    1. Genus: Festuca Tourn. ex L.
      1. Festuca idahoensis Elmer

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

    [GB]
    Habit
    Perennial; caespitose; clumped densely. Culms erect; 40-100 cm long. Leaves mostly basal. Leaf-sheaths smooth, or scaberulous. Ligule an eciliate membrane; 0.3-0.6 mm long. Leaf-blades filiform; conduplicate, or involute; 5-10 cm long; 0.5-1 mm wide. Leaf-blade surface scabrous.
    Inflorescences
    Inflorescence a panicle. Panicle open; linear; (5-)7-15(-20) cm long. Primary panicle branches appressed, or ascending. Spikelets solitary. Fertile spikelets pedicelled.
    Spikelets
    Spikelets comprising 4-8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10-13 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1-1.5 mm long; eventually visible between lemmas.
    Fertile
    Spikelets comprising 4-8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10-13 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1-1.5 mm long; eventually visible between lemmas.
    Glume
    Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2.5-5 mm long; 0.5-0.66 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate, or elliptic; 4-6.5 mm long; 0.9 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex acute.
    Florets
    Fertile lemma elliptic; 4.5-7.5 mm long; chartaceous; without keel; 5 -veined. Lemma surface smooth, or scaberulous. Lemma apex acute; awned; 1 -awned. Principal lemma awn 2-5 mm long overall. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.
    Flowers
    Anthers 3; 2.5-4 mm long.
    Fruits
    Caryopsis with adherent pericarp. Hilum linear.
    Distribution
    North America: northwest USA and southwest .
    Reference
    Poeae. Fl Pac NW 1993.

    Distribution

    Native to:

    Alberta, Arizona, British Columbia, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Saskatchewan, South Dakota, Utah, Washington, Wyoming

    Festuca idahoensis Elmer appears in other Kew resources:

    First published in Bot. Gaz. 36: 53 (1903)

    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

    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