Poaceae
Rostraria

Rostraria rohlfsii (Asch.) Holub

First published in Folia Geobot. Phytotax. 9: 272 (1974)
This species is accepted
The native range of this species is N. Central & NE. Sahara. It is an annual and grows primarily in the desert or dry shrubland biome.

Descriptions

Morphology General Habit
Annual; caespitose; clumped loosely. Culms erect, or geniculately ascending; 15-30 cm long; 2-5 -noded. Leaf-sheaths pubescent. Ligule an eciliate membrane; 0.5-1 mm long. Leaf-blades 2-10 cm long; 1.5-3 mm wide; flaccid. Leaf-blade surface pubescent. Leaf-blade apex abruptly acute; hardened.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle spiciform; linear, or lanceolate; 3-10 cm long; 0.6-1 cm wide. Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; 0.5-1 mm long.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 2-4 fertile florets; with diminished florets at the apex. Spikelets oblong, or obovate; laterally compressed; 4-5.5 mm long; breaking up at maturity; disarticulating below each fertile floret.
Fertile
Spikelets comprising 2-4 fertile florets; with diminished florets at the apex. Spikelets oblong, or obovate; laterally compressed; 4-5.5 mm long; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; dissimilar; reaching apex of florets; similar to fertile lemma in texture; gaping. Lower glume lanceolate; 3-3.5 mm long; 0.75 length of upper glume; membranous; without keels; 1-3 -veined. Lower glume lateral veins absent, or distinct. Lower glume surface pubescent. Lower glume apex acuminate. Upper glume elliptic; 4-5 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface glabrous. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile lemma oblong; 3-4 mm long; membranous; much thinner on margins; keeled; 3-5 -veined. Lemma midvein scabrous. Lemma surface asperulous; glabrous. Lemma apex dentate; 2 -fid; acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.8 way up back of lemma; 1-3 mm long overall. Palea gaping; hyaline. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Anthers 3; 0.5-0.7 mm long. Ovary glabrous.
Distribution
Africa: north.
Reference
Aveneae. FTA 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

    • 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