Poaceae
Eragrostis

Eragrostis patens Oliv.

First published in Trans. Linn. Soc. London 29: 175 (1875)
This species is accepted
The native range of this species is SW. Gabon to Kenya and S. Africa. It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

Gramineae, T. Cope. Flora Zambesiaca 10:2. 1999

Morphology General Habit
Caespitose annual; culms up to 35(45) cm tall, erect or ascending, branched or unbranched, glabrous at the nodes (but the internodes often pilose with tubercle-based hairs), eglandular; leaf sheaths glabrous or pilose with tubercle-based hairs; ligule a line of hairs; leaf laminas 3–18(25) cm × (1)2–3(6) mm, linear, flat, glabrous or sparsely pilose, eglandular.
Morphology Reproductive morphology Inflorescences
Panicle 2–10 cm long, very dense and spike-like, the spikelets sessile in cuneate clusters, these ± coalesced into an oval or oblong head, but sometimes the lowermost clusters distant, the primary branches not in whorls, terminating in a fertile spikelet, glabrous in the axils (but the axis often hirsute and the branchlets barbate).Spikelets 7–40 × 1–2 mm, linear, strongly laterally compressed, 8–70-flowered, the lemmas disarticulating from below upwards but the rhachilla breaking off above the glumes after the lower lemmas have begun to fall; glumes subequal, 2–2.5 mm long, reaching to between 1/2 and 2/3 the way along the adjacent lemmas, keeled, lanceolate in profile, scaberulous on the keel, otherwise glabrous, acute at the apex; lemmas 2.5–4 mm long, keeled, lanceolate in profile, membranous with distinct lateral nerves, closely appressed to the rhachilla, those in opposite rows imbricate and concealing the rhachilla, pallid or flushed with purple, scaberulous on the keel, otherwise glabrous, apiculate at the apex; palea persistent, glabrous on the flanks, the keels slender, wingless, minutely hispidulous; anthers 3, 0.2–0.3 mm long.
Morphology Reproductive morphology Fruits
Caryopsis c. 0.5 mm long, elliptic, laterally compressed.
[FZ]

Morphology General Habit
Annual; caespitose. Culms erect, or geniculately ascending; 6-40 cm long. Ligule a fringe of hairs. Leaf-blades 3-10 cm long; 2-3 mm wide.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle spiciform; oblong, or ovate; continuous, or interrupted (in cuneate clusters); 2-10 cm long; 1.5-6 cm wide. Panicle branches glabrous, or pilose. Spikelets solitary. Fertile spikelets pedicelled.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 8-70 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 7-40 mm long; 1-1.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas; fragile above; with the distal florets falling as a whole. Rhachilla internodes definite.
Fertile
Spikelets comprising 8-70 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 7-40 mm long; 1-1.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas; fragile above; with the distal florets falling as a whole. Rhachilla internodes definite.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes deciduous; similar; shorter than spikelet. Lower glume lanceolate; 2-2.5 mm long; 1 length of upper glume; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2-2.5 mm long; 0.6-0.8 length of adjacent fertile lemma; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Fertile florets appressed to rhachilla. Fertile lemma elliptic, or ovate; 2.5-4 mm long; membranous; pallid, or purple; keeled; 3 -veined. Lemma lateral veins distinct. Lemma apex apiculate. Palea 0.5 length of lemma. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.
Morphology Reproductive morphology Flowers
Anthers 3; 0.2 mm long.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; ellipsoid; 0.5 mm long.
Distribution
Africa: west-central tropical, east tropical, southern tropical, and south.
Reference
Eragrostideae. FTEA.
[GB]

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

Morphology General Habit
Tufted annual; culms 6–40 cm. high, erect or ascending.
Morphology Leaves
Leaf-blades flat, 3–10 cm. long, 2–3 mm. wide.
Morphology Reproductive morphology Inflorescences
Panicle spike-like, 2–10 cm. long, 1.5–6 cm. wide, the spikelets sessile in wedge-shaped clusters, these ± coalescent into an ovoid or oblong head, but sometimes the lower clusters distant; rhachis glabrous to hirsute, branchlets bearded.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets 8–70-flowered, linear, 7–40 mm. long, 1–1.5 mm. wide, pallid or flushed with purple, the florets closely appressed to the rhachilla, breaking up from the base, the rhachilla breaking off above the glumes soon after the lower lemmas commence to fall; glumes lanceolate, subequal, 2–2–5 mm. long, scarious; lemmas narrowly ovate-elliptic, 2.5–4 mm. long, membranous, apiculate; palea ± half as long as the lemma, minutely hispidulous on the keels, persistent; anthers 3, 0.2 mm. long.
Morphology Reproductive morphology Fruits
Caryopsis ellipsoid, 0.5 mm. long.
Figures
Fig. 64/1, 2, p. 226.
Habitat
Pathsides, overgrazed and weedy places; 400–2000 m.
Distribution
K2 K4 T1 T2 T3 T4 T5 T6 T7 T8 U1 U2 U3 U4 Congo (Brazzaville) to South Africa
[FTEA]

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

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • 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 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