Poaceae
Agrostis

Agrostis rossiae Vasey

First published in Contr. U.S. Natl. Herb. 3: 76 (1892)
This species is accepted
The native range of this species is Wyoming. It is a perennial and grows primarily in the temperate biome.

Descriptions

Morphology General Habit
Annual; caespitose. Culms 9-15 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths loose. Ligule an eciliate membrane; 1-2 mm long; erose. Leaf-blades flat, or conduplicate; 1-2.5 cm long; 1-2 mm wide. Leaf-blade surface scabrous; rough adaxially.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; ovate; 5-6 cm long; with spikelets clustered towards branch tips. Primary panicle branches ascending; whorled at most nodes. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2-2.5 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; 2-2.5 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; 2-2.5 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; 2-2.5 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 dentate; 4 -fid; truncate; muticous. Palea 0.6 mm long; 0.4-0.5 length of lemma; hyaline.
Morphology Reproductive morphology Flowers
Lodicules 2; membranous. Anthers 3; 0.4-0.5 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp. Hilum linear.
Distribution
North America: northwest USA.
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

  • 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