Poaceae
Aristida

Aristida gyrans Chapm.

First published in Bot. Gaz. 3: 18 (1878)
This species is accepted
The native range of this species is SE. U.S.A., Cuba to Hispaniola. It is a perennial and grows primarily in the subtropical biome.

Descriptions

Morphology General Habit
Perennial; caespitose. Culms erect; slender; 40-70 cm long. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades involute; 10-15 cm long; 1 mm wide. Leaf-blade surface scabrous; rough adaxially.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; linear; 15-30 cm long. Primary panicle branches appressed; bearing 1-3(-6) fertile spikelets on each lower branch. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 10-11 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 1.5 mm long; pubescent; pungent.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 10-11 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 1.5 mm long; pubescent; pungent.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume linear; 7-8 mm long; 0.7-0.8 length of upper glume; membranous; 2 -veined. Lower glume primary vein smooth. Lower glume apex setaceously attenuate. Upper glume linear; 10-11 mm long; membranous; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex setaceously attenuate.
Morphology Reproductive morphology Flowers Florets
Fertile lemma linear; subterete; 6 mm long; coriaceous; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex scabrous; with a short cylindrical neck; with this appendage 0.5 mm long; awned; 3 -awned. Principal lemma awn spreading; with 10-15 mm long limb. Lateral lemma awns gyrate; 10-15 mm long; subequal to principal.
Morphology Reproductive morphology Flowers
Anthers 3.
Distribution
North America: southeast USA.
Reference
Aristideae. N Amer Fl 1994.
[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

    • 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 2024. 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 2024. 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