Eleocharis retroflexa

(Poiret) Urban

Symb. Antill. 2: 165. 1900.

Illustrated
Basionym: Scirpus retroflexus Poiret in J. Lamarck et al., Encycl. 6: 753. 1804
Synonyms: Baeothryon retroflexum A. Dietrich Chaetocyperus niveus Liebmann Chaetocyperus polymorphus var. depauperatus Nees Chaetocyperus rugulosus Nees Chaetocyperus viviparus Liebmann Cyperus depauperatus Vahl Eleocharis depauperata Kunth
Treatment appears in FNA Volume 23. Treatment on page 98. Mentioned on page 61, 69, 97.

Plants annual, tufted, mat-forming, often stoloniferous, sometimes entirely vegetative; rhizomes absent. Culms erect, ascending or arching, pentagonal, sulcate, 1.5–10 cm × 0.2–0.3 mm [larger], soft. Leaves: distal leaf sheaths persistent or disintegrating, pale brown to green, red-spotted [mostly red-brown], membranous; apex acuminate. Spikelets: basal spikelets usually present, bisexual; often proliferous, ellipsoid or obovoid, laterally compressed, 1.7–3.9 × 1.2–2 mm, apex acute; proximal scale empty or with a flower, deciduous, amplexicaulous, similar to floral scales (sometimes 2.4–2.9 mm); subproximal scale with a flower; floral scales clearly distichous, 2–6 [or more], 4–6 per mm of rachilla, pale brown [marked red-brown], ovate or elliptic, 1.8–2.5 × 0.8–1.4 mm, membranous, apex rounded to obtuse, midribs green, keeled. Flowers: perianth bristles 6, colorless or pale brown, shorter than achenes; spinules not evident at 45X; stamens 3; anthers (0.55–)0.7 mm; styles 3-fid. Achenes stramineous (to cream), obovoid, trigonous or subterete, not compressed, angles prominent, 0.8 × 0.5–0.55 mm, apex not constricted proximal to tubercle, coarsely cancellate or honeycomb-reticulate at 10–15X. Tubercles red-brown, pyramidal, trigonous, proximally clearly to obscurely 3-lobed, lobes decurrent on achene angles, 0.3–0.35 × 0.3–0.4 mm.


Phenology: Fruiting summer.
Habitat: Freshwater ponds, stream banks, marshes, sandy or muddy soils
Elevation: 0–10 m

Distribution

V23 142-distribution-map.jpg

Ala., Mexico, West Indies, Bermuda, Central America, South America, Asia (including Indonesia), Pacific Islands, Australia.

Discussion

We have seen only one collection of Eleocharis retroflexa from the flora area (Mobile, Alabama, in 1896, US). Other populations are likely in the United States Gulf States. The broad-shouldered, strongly sculptured achenes, trilobed, decurrent tubercles, and basal spikelets are distinctive.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis retroflexa"
Jeremy J. Bruhl +  and S. Galen Smith +
(Poiret) Urban +
Scirpus retroflexus +
Ala. +, Mexico +, West Indies +, Bermuda +, Central America +, South America +, Asia (including Indonesia) +, Pacific Islands +  and Australia. +
0–10 m +
Freshwater ponds, stream banks, marshes, sandy or muddy soils +
Fruiting summer. +
Symb. Antill. +
Illustrated +
Baeothryon retroflexum +, Chaetocyperus niveus +, Chaetocyperus polymorphus var. depauperatus +, Chaetocyperus rugulosus +, Chaetocyperus viviparus +, Cyperus depauperatus +  and Eleocharis depauperata +
Eleocharis retroflexa +
Eleocharis (sect. Eleocharis) ser. Tenuissimae +
species +