Poaceae
Sporobolus

Sporobolus silveanus Swallen

First published in J. Washington Acad. Sci. 31: 350 (1941)
This species is accepted
The native range of this species is E. Central & SE. U.S.A. It is a perennial and grows primarily in the temperate biome.

Descriptions

Morphology General Habit
Perennial; caespitose; clumped densely. Butt sheaths papery; glossy. Culms erect; slender; 90-120 cm long. Culm-internodes antrorsely scabrous. Leaves mostly basal. Leaf-sheaths without keel; glabrous on surface, or pubescent. Ligule a fringe of hairs; 0.1-0.8 mm long. Leaf-blades curved, or flexuous; conduplicate, or involute; 15-30 cm long; 1-2 mm wide.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; ovate; 30-40 cm long; 10-12 cm wide; bearing few spikelets. Primary panicle branches ascending. Spikelets appressed, or ascending; solitary. Fertile spikelets pedicelled. Pedicels 5-8 mm long.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 5-6 mm long; breaking up at maturity; disarticulating below each fertile floret.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 5-6 mm long; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes deciduous; reaching apex of florets. Lower glume lanceolate; 3-4.5 mm long; 0.75 length of upper glume; membranous; purple; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume ovate; 4-6 mm long; 1 length of adjacent fertile lemma; membranous; purple; without keels; 3 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.
Morphology Reproductive morphology Flowers Florets
Fertile lemma ovate; 5-6 mm long; membranous; without keel; 1 -veined. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Palea keels approximate.
Morphology Reproductive morphology Flowers
Anthers 3-4 mm long; purple.
Morphology Reproductive morphology Fruits
Caryopsis with free soft pericarp; oblong; 2-2.5 mm long. Embryo 0.33 length of caryopsis.
Distribution
North America: south-central USA and southeast .
Reference
Eragrostideae. Gr Tex 1993.
[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

    • '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 2025. 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 2025. 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