Cenchrus riparius (Hochst. ex A.Rich.) Morrone

First published in Ann. Bot. (Oxford) 106: 129 (2010)
This species is accepted
The native range of this species is Ethiopia to E. Tropical Africa. It is a perennial or rhizomatous geophyte and grows primarily in the seasonally dry tropical biome.

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]

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit
Perennial, with long stout rhizomes and stolons forming a mat; culms 15–45 cm. high, somewhat spongy, ascending from a creeping base.
Morphology Leaves
Leaf-blades linear, 7–35 cm. long, 3–10 mm. wide, flat or folded.
Morphology Reproductive morphology Inflorescences
Panicle linear, 4–10 cm. long, often enclosed below by the uppermost sheath, rhachis with shallow angular ribs below the flat stumpless scars, scaberulous; involucre enclosing 1–3 sessile or shortly pedicelled (up to 0.5 mm.) spikelets, with or without an indistinct oblong stipe up to 0.5 mm.; bristles glabrous, the longest 6–15 mm.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets narrowly lanceolate, 6–12 mm. long, acute to acuminate; lower glume minute or suppressed; upper glume up to 1.5 mm. long; lower lemma 1/3–2/3 as long as the spikelet, barren; upper lemma as long as the spikelet, membranous.
Habitat
In swamps; 1800–2700 m.
Distribution
K3 K4 T2
[FTEA]

Morphology General Habit
Perennial; mat forming. Rhizomes elongated. Stolons present. Culms decumbent; 10-150 cm long. Ligule a fringe of hairs. Leaf-blades flat, or conduplicate; 4-30 cm long; 2-10 mm wide.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle; embraced at base by subtending leaf. Panicle spiciform; linear; 2-15 cm long. Primary panicle branches accrescent to a central axis; with sessile scars on axis. Panicle axis angular; scaberulous; glabrous; bearing deciduous spikelet clusters. Spikelets subtended by an involucre. Fertile spikelets sessile; 1-2 in the cluster. Involucre composed of bristles; oblong; 3-6 mm long; base obtuse. Involucral bristles deciduous with the fertile spikelets; numerous; with one conspicuously longer bristle; 7-15 mm long; terete; flexible; glabrous.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute, or acuminate; 6-10 mm long; falling entire; deciduous with accessory branch structures.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute, or acuminate; 6-10 mm long; falling entire; deciduous with accessory branch structures.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblate; 0.05 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate. Upper glume ovate; 0.25-0.33 length of spikelet; hyaline; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex obtuse, or acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret ovate; 0.8-1 length of spikelet; membranous; 5-7 -veined; acute. Fertile lemma ovate; 6-10 mm long; membranous; without keel; 5-7 -veined. Lemma margins flat. Lemma apex acute. Palea membranous.
Morphology Reproductive morphology Flowers
Lodicules absent. Anthers 3; 3 mm long; anther tip smooth. Styles connate below.
Distribution
Africa: northeast tropical and east tropical.
Reference
Paniceae. FTEA.
[GB]

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit
Perennial, with long stout stolons and rhizomes forming a low matted sward, or with tall ascending culms; culms 10–150 cm. high, ascending from a creeping base.
Morphology Leaves
Leaf-blades linear, 4–30 cm. long, 2–10 mm. wide, flat or folded.
Morphology Reproductive morphology Inflorescences
Panicle linear, 2–15 cm. long, often enclosed below by the uppermost sheath; rhachis with shallow angular ribs below the flat stumpless scars, scaberulous; involucre enclosing 1–2 subsessile spikelets, without a distinct stipe; bristles glabrous, the longest 7–15 mm.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets narrowly lanceolate, 6–10 mm. long, acute to acuminate; lower glume minute, up to 0.5 mm., upper glume 1/4–1/3 the length of the spikelet; lower lemma from 4/5 to as long as the spikelet, ♂ or barren, the upper similar in texture.
Habitat
In swamps; also semi-cultivated around habitations, being gathered and burnt to yield salt from the ashes; 1400–2600 m.
Distribution
K3 K4 T2 T7 U3
[FTEA]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • 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