Poaceae
Agrostis

Agrostis oregonensis Vasey

First published in Bull. Torrey Bot. Club 13: 56 (1886)
This species is accepted
The native range of this species is W. Canada to W. U.S.A. It is a perennial and grows primarily in the temperate biome.

Descriptions

Morphology General Habit
Perennial; caespitose. Culms 50-80 cm long. Lateral branches lacking. Ligule an eciliate membrane; 2-4 mm long; erose, or lacerate; obtuse, or acute. Leaf-blades 2-4 mm wide. Leaf-blade surface scaberulous.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; oblong; 10-30 cm long. Primary panicle branches ascending, or spreading; whorled at most nodes; 5-10 cm long. Panicle branches stiff. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.2-3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.2-3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 2.2-3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2.2-3 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile lemma elliptic; 1.5 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins extending close to apex. Lemma apex muticous. Palea 0.2 length of lemma; hyaline.
Morphology Reproductive morphology Flowers
Lodicules 2; 0.3 mm long; membranous. Anthers 3; 0.4-0.6 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp. Hilum linear.
Distribution
North America: northwest USA and southwest .
Reference
Aveneae. Fl Pac NW 1994.
[GB]

Sources

  • 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

    • 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 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 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 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0