1. Family: Poaceae Barnhart
    1. Genus: Calamagrostis Adans.
      1. Calamagrostis trichodonta (Wedd.) Soreng

        This species is accepted, and its native range is NW. Argentina.

    [GB]
    Habit
    Perennial; caespitose. Butt sheaths yellow; glabrous. Basal innovations intravaginal. Culms erect, or geniculately ascending; 15-38 cm long; 3 -noded; with 0.5 of their length below uppermost node; without nodal roots. Culm-internodes similar in length; terete; yellow; concolorous; striate; smooth. Culm-nodes flush with internodes; without obvious supra-nodal ridge; pallid; glabrous. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths loose; unthickened at base; open for most of their length; without keel; striately veined; smooth; glabrous on surface. Ligule an eciliate membrane; 1 mm long; membranous; lacerate. Collar concolorous; glabrous. Leaf-blade base symmetrical. Leaf-blades tapering towards tip; involute; 1.5-2.5 mm wide; concolorous. Leaf-blade midrib indistinct; scarcely raised beneath. Leaf-blade venation distinct. Leaf-blade surface smooth; glabrous; hairless throughout. Leaf-blade margins scaberulous. Leaf-blade apex acute; hooded.
    Inflorescences
    Inflorescence a panicle. Peduncle terete. Panicle open; oblong, or ovate; continuous; effuse; straight; 6-10 cm long; 2-3 cm wide; 0.33 of culm length. Primary panicle branches spreading; moderately spaced; 3 -nate; whorled at most nodes; 0.8-2 cm long; with lower 0.1-0.2 length of panicle; bearing 4-6 fertile spikelets on each lower branch. Panicle axis dominant, or distinct; 6-10 noded; with lower internodes 2.5 cm long; with rounded ribs; glandular; smooth. Panicle branches terete; multilateral; bearing approximate spikelets; glandular; with occasional prickles. Spikelets ascending; solitary. Fertile spikelets pedicelled. Pedicels linear; 0.2-0.5 length of fertile spikelet; tip widened.
    Spikelets
    Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; with obtuse base; laterally compressed; compressed moderately; 5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent; hairy on the margins and in 2 tufts; with subequal hairs. Floret callus hairs 0.5-1 mm long; 0.2-0.4 length of lemma (the two specimens available for inspection had callus hairs of this dimenstion. The original description however indicated that the hairs were two thirds the length of the lemma, but this has been found to refer to rhachilla extension).
    Fertile
    Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; with obtuse base; laterally compressed; compressed moderately; 5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent; hairy on the margins and in 2 tufts; with subequal hairs. Floret callus hairs 0.5-1 mm long; 0.2-0.4 length of lemma (the two specimens available for inspection had callus hairs of this dimenstion. The original description however indicated that the hairs were two thirds the length of the lemma, but this has been found to refer to rhachilla extension).
    Glume
    Glumes persistent; similar; subequal in width; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; symmetrical; not clasping; 5.5 mm long; 1.1 length of upper glume; 1 length of spikelet; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein extending to apex; pectinately ciliate. Lower glume lateral veins absent. Lower glume inner surface glabrous. Lower glume margins flat. Lower glume apex acute. Upper glume lanceolate; symmetrical; dorsally convex in profile; 3.8-5 mm long; 1-1.1 length of adjacent fertile lemma; 1 length of spikelet; narrower than lemma; pallid, or yellow; eglandular; 1-keeled; 3 -veined. Upper glume primary vein obscure; smooth. Upper glume lateral veins absent. Upper glume surface smooth; inner surface glabrous. Upper glume margins smooth. Upper glume apex acute.
    Florets
    Fertile lemma lanceolate; widest at 0.33 of its length from base; symmetrical; laterally compressed; dorsally convex along back; lanceolate in profile; 3.75-4.5 mm long; 1 mm wide; membranous; yellow; concolorous; without keel; rounded throughout; 0 -veined. Lemma midvein simple. Lemma lateral veins obscure; absent or obscure below. Lemma surface scabrous; rough above; unwrinkled, or rugulose; with basal hair tufts near margin; inner surface glabrous. Lemma apex dentate; 5 -fid; with simple equal lobes; with filiform lobes; with lobes 0.5-0.8 mm long; incised 0.2 of lemma length; acuminate; awned; 1 -awned. Principal lemma awn median; dorsal; arising 0.35-0.4 way up back of lemma; geniculate; ascending; simple at base; subterete below; stiff; attenuate; 5 mm long overall; 1.3 length of lemma; with 3 mm long limb; clearly exserted from spikelet; with twisted column; persistent; limb scaberulous, or scabrous. Column of lemma awn 2 mm long; 0.4 length of limb; scabrous. Palea present; free; embraced by lemma; linear; with flaps narrower than body; 2.5-3.2 mm long; 0.8 length of lemma; membranous; of uniform consistency; 2-keeled. Palea keels extending to apex; 0.7-1 mm apart; scaberulous. Palea surface scaberulous. Palea apex erose; truncate. Rhachilla extension 1.6 mm long; 0.3-0.4 length of fertile floret; approximately straight; pubescent; hairy throughout; with 0.5-3 mm long hairs.
    Flowers
    Lodicules 2. Anthers 3; linear; 3 mm long; eventually exserted; dehiscent by a longitudinal slit; pallid; anther tip smooth. Stigmas 2; retained within floret; white. Styles 1 mm long. Ovary glabrous.
    Fruits
    Disseminule comprising a caryopsis.
    Distribution
    South America: western South America and southern South America.
    Reference
    Aveneae. KTH 2006.

    Distribution

    Native to:

    Argentina Northwest

    Calamagrostis trichodonta (Wedd.) Soreng appears in other Kew resources:

    First published in Contr. U.S. Natl. Herb. 48: 223 (2003)

    Accepted by

    • 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
    • Zuloaga, F.O., Morrone, O. , Belgrano, M.J., Marticorena, C. & Marchesi, E. (eds.) (2008). Catálogo de las Plantas Vasculares del Cono Sur Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348.

    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