Poaceae
Andropogon

Andropogon arctatus Chapm.

First published in Bot. Gaz. 3: 20 (1878)
This species is accepted
The native range of this species is SE. U.S.A. It is a perennial and grows primarily in the subtropical 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. Culms 100-150 cm long. Lateral branches ample. Leaf-sheaths hirsute. Ligule an eciliate membrane. Leaf-blades erect; 15-30 cm long; 3-5 mm wide. Leaf-blade surface scabrous; rough adaxially; pubescent; hairy abaxially.
Morphology Reproductive morphology Inflorescences
Synflorescence compound; linear. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole linear; 3-5 cm long. Peduncle 3-5 cm long. Racemes 2; paired; 2.5-4 cm long. Rhachis fragile at the nodes; villous on margins. Rhachis hairs 3 mm long. Rhachis internodes linear; 2-3 mm long. Rhachis internode tip transverse; cupuliform; with simple rim. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 3-4 mm long; villous; with 3 mm long hairs.
Sterile
Companion sterile spikelets represented by single glumes; linear; 0.5-1.5 mm long; shorter than fertile.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5-6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse; inserted. Spikelet callus hairs 0.33 length of spikelet. Companion sterile spikelets represented by single glumes; linear; 0.5-1.5 mm long; shorter than fertile.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5-6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse; inserted. Spikelet callus hairs 0.33 length of spikelet.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; 2-keeled; keeled dorsally. Lower glume primary vein ciliate. Lower glume intercarinal veins absent. Lower glume surface deeply depressed. Upper glume lanceolate; membranous; 1-keeled. Upper glume primary vein ciliate. Upper glume margins ciliate. Upper glume muticous.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 7-12 mm long overall; with a straight or slightly twisted column. Column of lemma awn glabrous.
Morphology Reproductive morphology Flowers
Anthers 1.
Distribution
North America: southeast USA.
Reference
Andropogoneae. Man Gr US 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

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • 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