1. Family: Poaceae Barnhart
    1. Genus: Hilaria Kunth
      1. Hilaria rigida (Thurb.) Benth. ex Scribn.

        This species is accepted, and its native range is Mexico.

    [GB]
    Habit
    Perennial. Rhizomes elongated. Culms decumbent; 50-100 cm long. Culm-internodes distally woolly. Culm-nodes glabrous, or pubescent. Leaf-sheaths longer than adjacent culm internode; smooth, or antrorsely scabrous. Leaf-sheath oral hairs woolly. Ligule an eciliate membrane; 1 mm long; pubescent on abaxial surface (woolly). Leaf-blades involute; 2-5 cm long; 2-4 mm wide; coriaceous; stiff. Leaf-blade surface ribbed; smooth, or scabrous; glabrous, or woolly. Leaf-blade apex pungent.
    Inflorescences
    Inflorescence composed of racemes. Racemes borne along a central axis; closely spaced; in a multilateral false spike; cuneate; unilateral; 0.6-1.2 cm long; bearing a triad of spikelets. Central inflorescence axis 4-7 cm long. Rhachis obsolete; deciduous from axis. Raceme-bases brief; pilose. Spikelets in threes. Fertile spikelets pedicelled; 1 in the cluster. Companion sterile spikelets sessile; 2 in the cluster.
    Sterile
    Companion sterile spikelets well-developed; male; cuneate; asymmetrical; dorsally compressed; 6-12 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes free; membranous; 5-9 mm long; 5-7 -veined; ciliate on margins; lobed; 2-4 -fid; mucronate. Companion sterile spikelet lemmas 2-4; exserted from glumes; 2-4 mm long; dentate; 1-awned; with 2 mm long awn.
    Spikelets
    Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 6-12 mm long; falling entire; deciduous with accessory branch structures. Companion sterile spikelets well-developed; male; cuneate; asymmetrical; dorsally compressed; 6-12 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes free; membranous; 5-9 mm long; 5-7 -veined; ciliate on margins; lobed; 2-4 -fid; mucronate. Companion sterile spikelet lemmas 2-4; exserted from glumes; 2-4 mm long; dentate; 1-awned; with 2 mm long awn.
    Fertile
    Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 6-12 mm long; falling entire; deciduous with accessory branch structures.
    Glume
    Glumes free; shorter than spikelet. Lower glume oblong; asymmetrical; membranous; pallid; 1-keeled; 7 -veined. Lower glume margins ciliate. Lower glume apex lobed; 2 -fid; awned; 1-3 -awned. Lower glume awn dorsal; 3-6 mm long. Upper glume oblong; asymmetrical; 0.75 length of adjacent fertile lemma; membranous; pallid; 1-keeled; 7 -veined. Upper glume margins ciliate. Upper glume apex lobed; 2 -fid; awned; 1-3 -awned. Upper glume awn dorsal; 3-6 mm long.
    Florets
    Fertile florets bisexual. Fertile lemma lanceolate; laterally compressed; 6-12 mm long; membranous; keeled; 3 -veined. Lemma apex lobed; 2 -fid; incised 0.25 of lemma length; acute; awned; 1 -awned. Principal lemma awn from a sinus; 4 mm long overall.
    Flowers
    Lodicules 2; 0.1 mm long. Anthers 3; 4-4.5 mm long.
    Distribution
    North America: southwest USA and Mexico.
    Reference
    Cynodonteae. Swallen.

    Distribution

    Native to:

    Mexico Northeast, Mexico Northwest, Mexico Southwest

    Introduced into:

    New Mexico

    Hilaria rigida (Thurb.) Benth. ex Scribn. appears in other Kew resources:

    First published in Bull. Torrey Bot. Club 9: 86 (1882)

    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
    • Allred, K.W. (2012). Flora Neomexicana, ed. 2, 1: 1-599. Range Science Herbarium, Las Cruces, New Mexico.
    • Dávila, P., Mejia-Saulés, M.T., Gómez-Sánchez, N., Valdés-Reyna, J., Ortíz, J.J., Morín, C., Castrejón, J. & Ocampo, A. (2006). Catálogo de las Gramíneas de México: 1-671. CONABIO, México city.

    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