Eleocharis geniculata (L.) Roem. & Schult.

Cyperaceae, Miss S. S. Hooper. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit

Medium sized, closely tufted plant up to 40 cm. high

Morphology Reproductive morphology Inflorescences

Brownish, broadly ovate spikelets

Ecology

Brackish marshes, edges of mangrove swamps.

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Type

Jamaica, Herb. Clifford 21, Scirpus 1 (BM-000557653 lectotype), lectotypified by Furtado in Gard. Bull. Straits Settlem. 9: 299 (1937).

Morphology General Habit

Annual or short-lived perennial, closely tufted; often with inconspicuous fragile white stolons; adventitious roots shallow

Morphology Culms

Culms 12–15 cm × 0.6–0.9 mm, lengthening to c. 22 cm when fruiting, ridged; leaves few, reduced to small lobes terminating sheaths tinted reddish-purple

Morphology Reproductive morphology Inflorescences

Inflorescence a solitary ovoid spikelet, 3–4 × 2.5–3.5 mm, partially covered when young by 2 greenish bracts resembling glumes

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes greyish below to brown apically, 1.8–2 × 1.4–1.5 mm, imbricate, loosening as fruits mature, midribs obscure, apex rounded

Morphology Reproductive morphology Flowers Perianth

Perianth bristles c. 7, pink, softly glabrous, exceeding nutlet length

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3, filaments persisting on fruit until after dissemination

Morphology Reproductive morphology Flowers Gynoecium Style

Style bifid

Morphology Reproductive morphology Fruits

Nutlet biconvex, obovoid, 0.6–0.9 × 0.6–0.7 mm, smooth, shining purple/black at maturity; persistent style base conical, small.

Distribution

Zambia, Zimbabwe, Mozambique. Also in West Africa, Somalia, D.R. Congo, Uganda, Kenya, Tanzania, Namibia, South Africa (KwaZulu-Natal), and widely distributed in temperate and subtropical zones.

Ecology

Predominantly coastal along subtropical to temperate continental margins or adjacent to permanent waters of mangrove swamps and other temporary water bodies, rarely on inland lake margins; 5–1000 m.

Conservation

Widespread; not threatened.

Recognition

Similar in appearance to Eleocharis caduca. Bristles are reported to be glabrous but in the nutlet illustrated they are barbellate.

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Type

Lectotype: Jamaica, Herb. Clifford 21, Scirpus 1 (BM–000557653), chosen by Furtado in Gard. Bull. Straits Settlem. 9: 299 (1937)

Morphology General Habit

Annual herb with tufted culms from a compact base.

Morphology Culms

Culms 12–45 cm long, irregularly ridged, 0.6–0.9 mm thick.

Morphology Leaves Leaf sheaths

Sheath reddish or purple at base, greyish above, ending in a short triangular acute lobe with hyaline margin.

Morphology Roots

Root system shallow

Morphology Reproductive morphology Inflorescences Spikelets

Spikelet ovoid, 3–4 × 2.5–3.5 mm.

Morphology Reproductive morphology Inflorescences

Inflorescence bracts greenish, covering the glumes in bud.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes grey at base, brown at apex, 1.8–2 × 1.4–1.5 mm, rounded at apex, midrib obscure and sometimes green, margin slightly frayed.

Morphology Reproductive morphology Flowers Perianth

Perianth bristles ± 7, pink, glabrous, longer than the nutlet

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3, the filaments often persisting in fruit

Morphology Reproductive morphology Flowers Gynoecium Style

Style 2-branched

Morphology Reproductive morphology Fruits

Nutlet blackish purple, obovoid, 0.6–0.8 × 0.6–0.7 mm, smooth and shiny; appandage pale grey, minute and conical.

Ecology

Lake shores, swamps, mangrove; 0–1150 m

Distribution

Flora districts: U4 K7 T3 T6 P Range: West Africa from Senegal to Nigeria, Cameroon, Gabon, CongoKinshasa, Somalia, Zambia, Mozambique, Zimbabwe, Botswana; widely distrubuted in the temperate and subtropic zones of the World

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Annual, with fibrous roots

Morphology Culms

Culms densely tufted, mostly 5–20 cm tall; basal sheaths firm, oblique at apex

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets ovoid, obtuse, 2–6 mm long; glumes ovate, obtuse, yellowish or pale brown. Bristles 5–8, brown, longer than the achene

Morphology Reproductive morphology Flowers Gynoecium Style

Style 2-cleft

Morphology Reproductive morphology Fruits

Achenes ca. 1 mm long, shining black, with a short whitish tubercle.

Distribution

Grand Cayman. Pantropical, extending also into temperate regions.

Ecology

Usually a weed of wet ditches and damp open ground.

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

Bernal, R., G. Galeano, A. Rodríguez, H. Sarmiento y M. Gutiérrez. 2017. Nombres Comunes de las Plantas de Colombia. http://www.biovirtual.unal.edu.co/nombrescomunes/

Vernacular

junco

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/164219/140400096

Conservation

LC - least concern

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Tufted annual with crowded stems; stems 5–40 cm long and 0.6–1.2 mm thick, terete or angular

Morphology Leaves Leaf sheaths

Sheath grey above, purple below, ending in a short triangular acute lobe with thinner hyaline margin

Morphology Reproductive morphology Inflorescences Spikelets

Spikelet shortly ovate to almost globose, usually 3–4 x 2.5–3.5 mm, 20–50-flowered

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes 2–3 mm long, greyish below, brown above, rounded at the apex, margin usually somewhat frayed and without a distinct hyaline border

Morphology Reproductive morphology Flowers Perianth

Perianth-bristles 5–7, glabrous, longer than the nutlet

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3

Morphology Reproductive morphology Flowers Gynoecium Style

Style with 2 stigmas

Morphology Reproductive morphology Fruits

Nutlet c. 0.8 x 0.6 mm, obovate, biconvex, blackish-purple, smooth and shiny; appendage small, low-conical, pallid.

Distribution

N1–3; C2 pantropical, extending to South Africa.

Ecology

Altitude range: near sea-level to 1000 m.

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Nativa en Colombia; Alt. 0 - 1300 m.; Andes, Islas Caribeñas, Llanura del Caribe, Pacífico, Valle del Cauca, Valle del Magdalena.

Conservation

No Evaluada