Poaceae
Bromus

Bromus densus Swallen

First published in Contr. U.S. Natl. Herb. 29: 396 (1950)
This species is accepted
The native range of this species is NE. Mexico. 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: threatened. Confidence: confident
[AERP]

Morphology General Habit
Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 110 cm long. Culm-internodes antrorsely scabrous. Leaf-sheaths antrorsely scabrous; glabrous on surface. Ligule an eciliate membrane; 0.5 mm long; erose. Leaf-blades 10-25 cm long; 2-3 mm wide. Leaf-blade surface scabrous. Leaf-blade apex attenuate.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; lanceolate; dense; 9.5 cm long; 2 cm wide. Primary panicle branches appressed. Panicle branches scabrous. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose.
Fertile
Spikelets comprising 4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; shorter than spikelet. Lower glume lanceolate; 6-7 mm long; 0.66 length of upper glume; membranous; without keels; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 9-11 mm long; 0.66-0.75 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate.
Morphology Reproductive morphology Flowers Florets
Fertile lemma oblong; 12-13.5 mm long; chartaceous; without keel; 3 -veined. Lemma surface pilose; hairy below. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn subapical; 1-1.5 mm long overall. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Lodicules 2; membranous. Anthers 3. Ovary with a fleshy appendage above style insertion; pubescent on apex.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; hairy at apex; apex fleshy. Hilum linear.
Distribution
North America: Mexico.
Reference
Bromeae. Swallen 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