1. Family: Poaceae Barnhart
    1. Aira L.

      1. This genus is accepted, and its native range is Africa, Europe to Iran, Tibet to W. Himalaya.

    [GB]

    nonem

    Habit
    Annual. Culms erect, or geniculately ascending (4); slender (3/3); 2-22.87-55 cm long. Ligule an eciliate membrane. Leaf-blades filiform (6), or linear (2).
    Inflorescences
    Inflorescence a panicle; subtended by an unspecialized leaf-sheath (7), or an inflated leaf-sheath (1); exserted (7), or embraced at base by subtending leaf (1). Panicle open (7), or spiciform (1). Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform (7), or linear (1); tip widened (1/4), or globular (1/4), or pyriform (2/4).
    Spikelets
    Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong, or ovate (6); laterally compressed; 1.3-2.485-4.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets. Floret callus pubescent.
    Fertile
    Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong, or ovate (6); laterally compressed; 1.3-2.485-4.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets. Floret callus pubescent.
    Glume
    Glumes persistent; reaching apex of florets (1), or exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume ovate; 1 length of upper glume; membranous; 1-keeled; 1 -veined, or 2-3 -veined (6). Lower glume lateral veins absent (4), or obscure (2), or distinct (4). Lower glume apex entire, or erose (1); obtuse (3), or acute (5); muticous (7), or mucronate (2). Upper glume ovate; 1-1.287-1.5 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined, or 2-3 -veined (6). Upper glume apex obtuse (3), or acute (5); muticous (7), or mucronate (2).
    Florets
    Fertile lemma ovate; laterally compressed; lanceolate in profile (6/6); cartilaginous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface scaberulous (6), or scabrous (2). Lemma margins involute; covering most of palea. Lemma apex dentate; 2 -fid (7), or 3 -fid (1); muticous (1), or awned; 1 -awned. Principal lemma awn dorsal; geniculate. Palea 0.7 length of lemma; membranous (2), or cartilaginous (6); 2 -veined (6/6).
    Flowers
    Lodicules 2; membranous. Anthers 3. Stigmas 2.
    Fruits
    Caryopsis with adherent pericarp (6/6); fusiform (4/4); isodiametric (4/4); biconvex (4/4); smooth (4/4); apex unappendaged (6/6). Embryo 0.2 length of caryopsis. Hilum punctiform (6/6).
    Distribution
    Europe, or Africa (5), or Temperate Asia (3), or Tropical Asia (1), or Australasia (5), or Pacific (1), or North America (3), or South America (3), or Antarctica (2).
    [FTEA]

    Gramineae, W. D. Clayton, S. M. Phillips And S. A. Renvoize. Flora of Tropical East Africa. 1974

    Habit
    Small annuals, with slender culms and delicate open, or sometimes contracted, panicles
    Spikelets
    Spikelets small, 2-flowered, both florets bisexual, the rhachilla glabrous and very short between the florets, minutely produced beyond the upper floret; glumes delicately membranous, 1-nerved, glabrous; lemma lanceolate, shorter than the glumes, faintly 5-nerved, 2-toothed, rounded on the back, dorsally awned or awnless; callus minute, obtuse; stamens 3; stigmas 2
    Distribution
    Species ± 8; mainly in the Mediterranean region, but extending from Scandinavia to South Africa; several species have become naturalized in other temperate regions of the world.
    [FZ]

    Gramineae, E. Launert. Flora Zambesiaca 10:1. 1971

    Lodicules
    Lodicules 2.
    Stamens
    Stamens 3.
    Pistil
    Ovary glabrous; styles distinct, short, stigmas plumose, rather short, laterally exserted.
    Fruits
    Caryopsis oblong to narrowly elliptic in outline, tightly enclosed by the lemma and palea; hilum oblong, rather small; embryo subcircular, 1/3-1/4 the length of the caryopsis.
    Habit
    Small annuals.
    Ligules
    Ligule a membrane.
    Inflorescences
    Inflorescence a panicle, many-flowered, usually open.
    Spikelets
    Spikelets strongly laterally compressed, pedicelled, rather small, strictly 2-flowered, awned or rarely muticous; rhachilla disarticulating above the glumes and between the florets, very shortly produced beyond the superior floret, glabrous; florets 2, both bisexual, similar.
    Glume
    Glumes 2, subequal and similar, persistent, thinly membranous, usually hyaline, exceeding the florets except for the awns, 1-nerved, keeled, muticous.
    Lemma
    Lemmas shorter than the glumes, subequal, slightly distant, broadly lanceolate, dorsally rounded, faintly 5-nerved, very thinly membranous, hyaline, broadly lanceolate, with the apex acute to acuminate and usually shortly 2-dentate, margins usually involute, dorsally awned from beneath the middle, rarely awnless; awn geniculate, twisted below the bend (straight when moistened); callus rather short, obtuse, pilose or glabrous.
    Palea
    Paleas slightly shorter than the corresponding lemmas, 2-nerved, 2-keeled, narrowly oblong, with the apex 2-dentate.

    Images

    Distribution

    Native to:

    Albania, Algeria, Austria, Azores, Baleares, Baltic States, Belarus, Belgium, Bulgaria, Cameroon, Canary Is., Cape Verde, Corse, Cyprus, Czechoslovakia, Denmark, East Aegean Is., Ethiopia, Finland, France, Føroyar, Germany, Great Britain, Greece, Gulf of Guinea Is., Hungary, Iran, Ireland, Italy, Kenya, Kriti, Krym, Lebanon-Syria, Libya, Madagascar, Madeira, Malawi, Morocco, Netherlands, Nigeria, North Caucasus, Norway, Palestine, Poland, Portugal, Romania, Rwanda, Sardegna, Sicilia, Spain, Sudan, Sweden, Switzerland, Tanzania, Tibet, Transcaucasus, Tunisia, Turkey, Turkey-in-Europe, Uganda, Ukraine, West Himalaya, Yugoslavia, Zaïre

    Introduced into:

    Alabama, Argentina Northeast, Argentina Northwest, Argentina South, Brazil South, British Columbia, California, Cape Provinces, Chatham Is., Chile Central, Chile South, Connecticut, Costa Rica, Crozet Is., Delaware, District of Columbia, Falkland Is., Free State, Hawaii, Juan Fernández Is., Kerguelen, Korea, KwaZulu-Natal, Lesotho, Marquesas, Maryland, Masachusettes, Mauritius, Mexico Northwest, Mexico Southwest, New Jersey, New Mexico, New South Wales, New York, New Zealand North, New Zealand South, Norfolk Is., North Carolina, Nova Scotia, Oregon, Pennsylvania, Queensland, South Australia, Tasmania, Tennessee, Tristan da Cunha, Uruguay, Victoria, Virginia, Washington, Western Australia

    Aira L. appears in other Kew resources:

    First published in Sp. Pl.: 63 (1753)

    Accepted by

    • Govaerts, R.H.A. (2011). World checklist of selected plant families published update Facilitated by the Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Flora of West Tropical Africa
    • F.T.A. 10: 87 (1937).
    • Gen. Pl. ed. 5: 31 (1754)
    • Sp. Pl. 63 (1753)
    Flora Zambesiaca
    • Gen. Pl., ed. 5: 31 (1754).
    • Sp. Pl. 1: 63 (1753)
    Flora of Tropical East Africa
    • L., Gen. Pl., ed. 5: 31 (1754)
    • Sp. Pl.: 63 (1753)

    Sources

    Flora Zambesiaca
    Flora Zambesiaca
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    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