1. Family: Poaceae Barnhart
    1. Genus: Diarrhena P.Beauv.
      1. Diarrhena americana P.Beauv.

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

    [GB]
    Habit
    Perennial. Rhizomes elongated; scaly. Culms erect; 50-120 cm long. Ligule an eciliate membrane. Leaf-blades linear, or lanceolate; 25-50 cm long; 8-20 mm wide. Leaf-blade venation with obscure cross veins.
    Inflorescences
    Inflorescence a panicle. Panicle open; lanceolate; 8-25 cm long. Spikelets solitary. Fertile spikelets pedicelled.
    Spikelets
    Spikelets comprising 3-5 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10-18 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas.
    Fertile
    Spikelets comprising 3-5 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10-18 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas.
    Glume
    Glumes persistent; dissimilar; shorter than spikelet. Lower glume lanceolate; 0.5 length of upper glume; cartilaginous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 0.66 length of adjacent fertile lemma; cartilaginous; 1-keeled; 3-5 -veined. Upper glume apex acute.
    Florets
    Fertile florets divergent; free at tip. Fertile lemma elliptic; 6-10 mm long; cartilaginous; much thinner on margins; without keel; rounded except near apex; 3 -veined. Lemma lateral veins convergent above. Lemma apex cuspidate; awned; 1 -awned. Principal lemma awn pungent; 0.5-1 mm long overall. Palea 2 -veined. Palea apex obtuse. Apical sterile florets resembling fertile though underdeveloped.
    Flowers
    Lodicules 2; membranous. Anthers 2-3.
    Fruits
    Caryopsis with tardily free pericarp; ellipsoid; exposed between gaping lemma and palea at maturity; apex umbonate.
    Distribution
    North America: north-central USA, northeast USA, south-central USA, and southeast USA.
    Reference
    Diarrheneae. Gould.

    Distribution

    Native to:

    Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, North Carolina, Ohio, Oklahoma, Ontario, South Dakota, Tennessee, Texas, Virginia, West Virginia, Wisconsin

    Diarrhena americana P.Beauv. appears in other Kew resources:

    First published in Ess. Agrostogr.: 142 (1812)

    Accepted by

    • Lea, C. (2012). Diarrhena obovata in the Potomac River Watershed: A new invader? Castanea 77: 172-178.
    • 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