1. Family: Poaceae Barnhart
    1. Genus: Chasmanthium Link
      1. Chasmanthium laxum (L.) H.O.Yates

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

    [GB]
    Habit
    Perennial; caespitose. Rhizomes short; knotty. Culms 70-150 cm long. Leaf-sheaths glabrous on surface (rarely), or pubescent, or hirsute. Ligule a ciliolate membrane. Collar pubescent. Leaf-blades 10-40 cm long; 4-12 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy adaxially.
    Inflorescences
    Inflorescence a panicle. Panicle contracted, or glomerate; linear; interrupted; 15-50 cm long. Primary panicle branches 0.5-9 cm long. Spikelets solitary. Fertile spikelets pedicelled, or sessile.
    Spikelets
    Spikelets comprising 1-2 basal sterile florets; 2-4 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 5-8 mm long; 3-5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite.
    Fertile
    Spikelets comprising 1-2 basal sterile florets; 2-4 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 5-8 mm long; 3-5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite.
    Glume
    Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 1-2.5 mm long; 1 length of upper glume; herbaceous; 1-keeled; 1-3 -veined. Lower glume apex acute. Upper glume ovate; 1-2.5 mm long; 0.33-0.5 length of adjacent fertile lemma; herbaceous; 1-keeled; 3 -veined. Upper glume apex acute.
    Florets
    Basal sterile florets similar; barren; without significant palea; persisting on inflorescence. Lemma of lower sterile floret similar to upper glume; ovate; 1.5-2.5 mm long; herbaceous; 1-keeled; 3-5 -veined; acute. Fertile florets increasing in size upwards. Fertile lemma ovate; 3-5 mm long; herbaceous; keeled; 7-9 -veined. Lemma apex acuminate. Palea gaping; bowed outwards; 0.8 length of lemma; 2 -veined. Palea keels winged; narrowly winged; scabrous. Apical sterile florets distinct from fertile; 1 in number; male; linear; 3 mm long.
    Flowers
    Lodicules 2; cuneate; fleshy. Anthers 1; 1.5-2 mm long.
    Fruits
    Caryopsis with adherent pericarp; ovoid; laterally compressed; exposed between gaping lemma and palea at maturity; 2-3 mm long. Embryo 0.5 length of caryopsis.
    Distribution
    North America: north-central USA, northeast USA, south-central USA, and southeast USA.
    Reference
    Centotheceae. Gould.

    Images

    Distribution

    Native to:

    Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, Missouri, New York, North Carolina, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia

    Chasmanthium laxum (L.) H.O.Yates appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Benke, H. C. [4874], Tennessee Uniola laxa K000674845

    First published in S. W. Naturalist 11: 433 (1966)

    Accepted by

    • Flora of North America Editorial Committee (2003). Flora of North America North of Mexico 25: 1-781. Oxford University Press, New York, Oxford.
    • Govaerts, R. (1999). World Checklist of Seed Plants 3(1, 2a & 2b): 1-1532. MIM, Deurne.

    Literature

    Kew Backbone Distributions
    • Flora of North America Editorial Committee (2003). Flora of North America North of Mexico 25: 1-781. 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 2019. 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 2019. 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