Poaceae
Eragrostis

Eragrostis swallenii Hitchc.

First published in J. Washington Acad. Sci. 23: 451 (1933)
This species is accepted
The native range of this species is S. Texas to Mexico. It is a perennial and grows primarily in the seasonally dry tropical biome.

Descriptions

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]

Morphology General Habit
Perennial; caespitose. Glands annular. Culms 40-70 cm long. Culm-internodes glandular (below nodes). Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades 10-20 cm long; 2-4 mm wide. Leaf-blade surface glabrous; hairless except near base.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; ovate; 15-25 cm long; 10-15 cm wide. Primary panicle branches ascending, or reflexed; simple; 3-12 cm long. Panicle branches flexuous; glabrous in axils. Spikelets solitary. Fertile spikelets pedicelled. Pedicels glandular.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 8-25 fertile florets; with diminished florets at the apex. Spikelets linear, or lanceolate; laterally compressed; 6-16 mm long; 1.5-2.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas; fragile above. Rhachilla internodes obscured by lemmas.
Fertile
Spikelets comprising 8-25 fertile florets; with diminished florets at the apex. Spikelets linear, or lanceolate; laterally compressed; 6-16 mm long; 1.5-2.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas; fragile above. Rhachilla internodes obscured by lemmas.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes deciduous; similar; shorter than spikelet. Lower glume ovate; 1.4 mm long; 0.7-0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 1.8 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; 2 mm long; membranous; dark green; keeled; 3 -veined. Lemma lateral veins prominent. Lemma apex acute. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Lodicules 2; cuneate; fleshy.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; ellipsoid; 1 mm long.
Distribution
North America: south-central USA and Mexico.
Reference
Eragrostideae. Gr Texas 1994.
[GB]

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

    • 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 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