Poaceae
Aira

Aira praecox L.

First published in Sp. Pl.: 65 (1753), nom. cons.
This species is accepted
The native range of this species is Macaronesia, Europe to NW. Türkiye. It is an annual and grows primarily in the temperate biome.

Descriptions

Morphology General Habit
Annual. Culms erect; 2-25 cm long; 2-3 -noded. Leaves mostly basal. Ligule an eciliate membrane; 1.5-3.5 mm long; entire; obtuse. Leaf-blades filiform; involute; 0.5-5 cm long; 0.3-0.5 mm wide. Leaf-blade surface smooth, or scaberulous. Leaf-blade apex acute.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle spiciform; linear, or oblong; 0.5-4.5 cm long; 0.2-0.8 cm wide. Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; terete; 1-3 mm long.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong to ovate; laterally compressed; 3-3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets (florets arising at about the same level). Floret callus pubescent.
Fertile
Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong to ovate; laterally compressed; 3-3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets (florets arising at about the same level). Floret callus pubescent.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume ovate; 3-3.5 mm long; 1 length of upper glume; membranous; much thinner above; much thinner on margins; 1-keeled; keeled above; 1-3 -veined. Lower glume primary vein scaberulous. Lower glume apex acute. Upper glume ovate; 3-3.5 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; keeled above; 1-3 -veined. Upper glume primary vein scaberulous. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; laterally compressed; lanceolate in profile; 2.7-3.1 mm long; cartilaginous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface scaberulous; rough above. Lemma margins involute; covering most of palea. Lemma apex dentate; 3 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.3-0.4 way up back of lemma; geniculate; 3.4-4.3 mm long overall; with twisted column. Palea elliptic; 0.7 length of lemma; cartilaginous; 2 -veined. Palea apex obtuse.
Morphology Reproductive morphology Flowers
Lodicules 2; lanceolate; membranous. Anthers 3; 0.25-0.3 mm long. Stigmas 2; protandrous; laterally exserted.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; fusiform; isodiametric; biconvex; estipitate; without sulcus; smooth; apex unappendaged. Embryo 0.2 length of caryopsis. Hilum punctiform. Endosperm farinose. Disseminule comprising a floret.
Distribution
Europe: northern, central, southwestern, and eastern. Africa: Macaronesia. Asia-temperate: Caucasus and western Asia. Australasia: Australia and New Zealand. North America: western Canada, eastern Canada, northwest USA, northeast USA, southwest USA, and southeast USA. South America: southern South America. Antarctic: Subantarctic islands.
Reference
Aveneae. TAC.
[GB]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Common Names

english
early hair grass

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • GrassBase - The Online World Grass Flora

    • Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). 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 Vascular Plants 2026. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Living Collection Database

    • Common Names from Kew's Living Collection Database

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2026. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0