Poaceae
Agrostis

Agrostis lacuna-vernalis P.M.Peterson & Soreng

First published in J. Bot. Res. Inst. Texas 5: 422 (2011)
This species is accepted
The native range of this species is California. It is an annual and grows primarily in the subtropical biome.

Descriptions

Morphology General Habit
Annual; caespitose; clumped loosely. Basal innovations intravaginal. Culms erect, or geniculately ascending, or decumbent; slender; (1.5-)5-30 cm long; 0.25 mm diam.; 2-3 -noded. Culm-internodes smooth. Culm-nodes brown; glabrous. Lateral branches lacking. Leaves basal and cauline. Leaf-sheaths open for most of their length; mostly shorter than adjacent culm internode. Ligule an eciliate membrane; 1.2-1.7 mm long; erose; obtuse, or acute. Leaf-blades flat, or conduplicate, or involute; (1.4-)5-11 cm long; 0.3-1(-1.5) mm wide. Leaf-blade surface scabrous; rough abaxially; glabrous. Leaf-blade margins scaberulous.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle; comprising 12-90(-100) fertile spikelets. Panicle spiciform; linear; 1-7.5 cm long; 0.1-0.6 cm wide. Primary panicle branches 1-3 -nate; 0.6-1.4 cm long. Panicle branches capillary; scabrous. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 1.5-2.4 mm long; breaking up at maturity; disarticulating below each fertile floret.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 1.5-2.4 mm long; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume ovate; 1.5-2.4 mm long; 1 length of upper glume; herbaceous, or scarious; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume surface asperulous. Lower glume apex acute. Upper glume ovate; 1.5-2.4 mm long; herbaceous, or scarious; 1-keeled. Upper glume primary vein scaberulous. Upper glume surface scabrous. Upper glume margins scaberulous. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; 1.1-1.5 mm long; hyaline; light green and purple (at tip); shiny; without keel; 5 -veined. Lemma midvein extending to apex. Lemma lateral veins obscure. Lemma surface smooth; glabrous. Lemma apex truncate, or obtuse; muticous. Palea 0.7-1.1 mm long; 0.5-0.66 length of lemma; hyaline. Palea apex obtuse.
Morphology Reproductive morphology Flowers
Lodicules 2; 0.4-0.5 mm long. Anthers 3; 0.4-0.7 mm long; yellow. Ovary glabrous.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; ellipsoid; dorsally compressed; sulcate on hilar side; 0.9-1.2 mm long; light brown. Embryo 0.25 length of caryopsis. Hilum punctiform.
Distribution
North America: southwest USA.
Reference
Aveneae. Peterson & Soreng 2012.
[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: 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

  • 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 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