Echinochloa stagnina (Retz.) P.Beauv.

First published in Ess. Agrostogr.: 161 (1812)
This species is accepted
The native range of this species is Africa, Tropical Asia. It is an annual or perennial and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Perennial. Rhizomes elongated. Culms decumbent, or prostrate; 30-200 cm long; spongy; rooting from lower nodes. Culm-nodes glabrous, or bearded. Leaf-sheaths glabrous on surface, or hispid (rarely). Ligule a fringe of hairs. Leaf-blades 10-45 cm long; 3-20 mm wide.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes borne along a central axis; simply spaced, or closely spaced; flexuous; unilateral; 2-8 cm long; simple. Central inflorescence axis 6-25 cm long. Rhachis angular. Spikelet packing irregular; 4 -rowed. Spikelets in pairs. Fertile spikelets sessile.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; gibbous; acuminate; 3.5-6 mm long; falling entire.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; gibbous; acuminate; 3.5-6 mm long; falling entire.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.25-0.75 length of spikelet; membranous; without keels; 3-5 -veined. Lower glume surface hispidulous; with simple hairs, or tubercle-based hairs. Lower glume apex cuspidate. Upper glume ovate; membranous; without keels; 5 -veined. Upper glume surface hispidulous; with simple hairs, or tubercle-based hairs. Upper glume hairs 1 mm long. Upper glume apex acuminate; muticous, or awned; 1 -awned. Upper glume awn 0-4 mm long.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; hispidulous; with simple hairs, or tubercle-based hairs; bearing hairs 1 mm long; acuminate; awned. Awn of lower sterile floret (1-)3-20(-50) mm long. Fertile lemma ovate; gibbous; 3-5 mm long; indurate; much thinner above; shiny; without keel; 5 -veined. Lemma margins involute. Lemma apex acute; laterally pinched. Palea reflexed at apex; indurate.
Morphology Reproductive morphology Flowers
Anthers 3.
Distribution
Africa: north, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-tropical: India, Indo-China, Malesia, and Papuasia.
Reference
Paniceae. FTEA.
[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]

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/177001/1459889

Conservation
LC - least concern
[IUCN]

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

Morphology General Habit
Rhizomatous perennial (sometimes behaving as an annual); culms spongy, 30–200 cm. high, decumbent and rooting at the nodes; nodes sometimes bearded.
Morphology Leaves
Leaf-blades 10–45 cm. long, 3–20 mm. wide; ligule a line of hairs; sheaths glabrous or rarely hispid.
Morphology Reproductive morphology Inflorescences
Inflorescence ovate to narrowly lanceolate, 6–25 cm. long, typically open with the racemes secund, flexuous and ± nodding, but displaying much variation; racemes simple, 2–8 cm. long, coarsely spiculate.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets narrowly ovate, 3.5–6 mm. long, hispid, often from tubercles (rarely glabrescent); lower glume often long, 1/2–3/4 the length of the spikelet; upper glume awnless or with an awn up to 4 mm. long; lower floret ♂ or barren, tapering to an awn (1–)3–20(–50) mm. long; upper lemma 3–5 mm. long.
Habitat
Streamsides and pond margins, growing in water; sometimes floating in deep water, or collapsed in a tangle on mud after recession of flood; 0–2100 m.
Distribution
K2 K4 K6 K7 T1 T2 T3 T4 T5 T6 T7 U1 U2 U3 tropical AfricaMadagascarAssam to Indo-China
[FTEA]

Common Names

English
Hippo grass, Long-awned water grass, Water grass

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/
  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/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
  • Plants and People Africa

    • Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
    • © Plants and People Africa http://www.plantsandpeopleafrica.com http://creativecommons.org/licenses/by/3.0/