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  1. Family: Poaceae Barnhart
    1. Genus: Calamagrostis Adans.
      1. Calamagrostis divaricata P.M.Peterson & Soreng

        This species is accepted, and its native range is Mexico (Durango).

    [GB]
    Habit
    Perennial; caespitose; clumped loosely. Rhizomes short. Basal innovations extravaginal. Culms erect, or geniculately ascending; 52-96 cm long. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths 8-20 cm long; subequal to internodes; glabrous on surface. Ligule a ciliolate membrane; 2-3.6 mm long; entire, or lacerate; obtuse, or acute. Leaf-blades flat, or involute; 15-60 cm long; 1-3 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous.
    Inflorescences
    Inflorescence a panicle. Panicle open; ovate; loose; 9-16 cm long; 4-10 cm wide. Primary panicle branches ascending, or spreading; 3-6 -nate; whorled at most nodes; 2-8 cm long. Panicle axis scaberulous. Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1-5 mm long; scaberulous.
    Spikelets
    Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3.4-4.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent, or pilose. Floret callus hairs 0.2-1 mm long; 0.05-0.25 length of lemma.
    Fertile
    Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3.4-4.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent, or pilose. Floret callus hairs 0.2-1 mm long; 0.05-0.25 length of lemma.
    Glume
    Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 3.4-4.3 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume lanceolate; 3.4-4.3 mm long; 1.1-1.2 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous. Upper glume apex acute, or acuminate.
    Florets
    Fertile lemma lanceolate; 3.8-4.3 mm long; membranous; without keel; 5 -veined. Lemma surface scaberulous. Lemma apex awned; 1 -awned. Principal lemma awn dorsal; arising 0.66-0.75 way up back of lemma; geniculate; 4-6 mm long overall; with a straight or slightly twisted column. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Rhachilla extension 1.6-1.9 mm long; pilose; with 1-1.5 mm long hairs.
    Flowers
    Lodicules 2; lanceolate; 0.7-0.8 mm long. Anthers 3; 1.8-2.2 mm long; yellow. Stigmas 2. Ovary glabrous.
    Fruits
    Caryopsis with adherent pericarp; fusiform; 1.8-2.5 mm long; light brown. Hilum punctiform. Disseminule comprising a floret.
    Distribution
    North America: Mexico.
    Reference
    Aveneae. Peterson et al 2006.

    Distribution

    Native to:

    Mexico Northeast

    Other Data

    Calamagrostis divaricata P.M.Peterson & Soreng appears in other Kew resources:

    Bibliography

    First published in Sida 21: 315 (2004)

    Accepted by

    • Soreng, R.J., Davidse, G., Peterson, P.M., Zuloaga, F.O., Judziewicz, E.J., Filgueiras, T.S. & Morrone, O. (eds.) (2005). Catalogue of New World Grasses project. TROPICOS,the Missouri Botanical Garden's on-line taxonomic database http://mobot.mobot.org/W3T/Search/nwgc.html.

    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 2020. 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 2020. 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