Poaceae
Trisetum

Trisetum flavescens (L.) P.Beauv.

First published in Ess. Agrostogr.: 88 (1812)
This species is accepted
The native range of this species is Azores, Europe to Medit. and N. Iran. It is a perennial and grows primarily in the temperate biome.

Descriptions

Morphology General Habit
Perennial; caespitose. Butt sheaths pilose. Culms erect, or geniculately ascending; 20-80(-100) cm long; 2-5 -noded. Ligule an eciliate membrane; 0.3-1.1 mm long. Leaf-blades 3.5-12 cm long; 2-5 mm wide. Leaf-blade surface glabrous, or pubescent. Leaf-blade apex acuminate.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; elliptic; 7-15 cm long; 1.5-7 cm wide. Panicle branches scaberulous. Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1-4 mm long; scaberulous.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 2-4 fertile florets; with diminished florets at the apex. Spikelets oblong, or cuneate; laterally compressed; 5-7(-8) mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent. Floret callus pubescent.
Fertile
Spikelets comprising 2-4 fertile florets; with diminished florets at the apex. Spikelets oblong, or cuneate; laterally compressed; 5-7(-8) mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent. Floret callus pubescent.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; dissimilar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 2.5-4.7 mm long; 0.66-0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 4.3-6.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume apex acuminate.
Morphology Reproductive morphology Flowers Florets
Fertile lemma obovate; 4.4-6.3 mm long; chartaceous; much thinner above; much thinner on margins; yellow; shiny; keeled; 5 -veined. Lemma surface asperulous; rough above. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5-0.66 way up back of lemma; geniculate; 5-9 mm long overall; with twisted column. Palea gaping; hyaline. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Anthers 3; 1.3-2.5(-2.8) mm long. Ovary glabrous.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; linear. Hilum punctiform.
Distribution
Europe: northern, central, southwestern, southeastern, and eastern. Africa: north and Macaronesia. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, and western Asia. Asia-tropical: India and Papuasia. Australasia: Australia. Pacific: north-central. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, and southwest USA. South America: southern South America.
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]

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 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

  • Kew Science Photographs

    • Copyright applied to individual images