Poaceae
Arrhenatherum

Arrhenatherum pallens (Link) Link

First published in Hort. Berol. 1: 124 (1827)
This species is accepted
The native range of this species is CW. & SW.Portugal. It is a perennial and grows primarily in the subtropical biome.

Descriptions

Morphology General Habit
Perennial; caespitose. Culms 30-70 cm long. Culm-nodes glabrous. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane. Leaf-blades filiform; convolute; 0.6-0.8 mm wide. Leaf-blade surface ribbed; glabrous.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; lanceolate; dense; 5-12 cm long. Primary panicle branches bearing spikelets almost to the base. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 9-10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated below proximal fertile floret. Floret callus pilose.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 9-10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated below proximal fertile floret. Floret callus pilose.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; dissimilar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 7-8 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins obscure. Lower glume apex acuminate. Upper glume lanceolate; 9-10 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets male; with palea; attached to and deciduous with the fertile. Lemma of lower sterile floret elliptic; 7-8 mm long; chartaceous; much thinner above; pubescent; dentate; 2 -fid; acute, or acuminate; awned. Awn of lower sterile floret dorsal; arising 0.5-0.8 way up back of lemma; geniculate; 12-15 mm long. Fertile lemma elliptic; 7-8 mm long; chartaceous; much thinner above; without keel; 7 -veined. Lemma surface pubescent. Lemma apex acuminate; muticous, or awned; 1 -awned. Principal lemma awn subapical; 0-2 mm long overall. Palea 6-7 mm long. Palea keels ciliolate.
Morphology Reproductive morphology Flowers
Anthers 3. Ovary pubescent all over.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp.
Distribution
Europe: southwestern.
Reference
Aveneae. Fl Eur 1993.
[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: low confidence
[AERP]

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/162185/116536133

Conservation
VU - vulnerable
[IUCN]

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/

  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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 Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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