Scirpus confervoides Poiret in J. Lamarck et al., Encycl. 6: 755. 1805; Rhynchospora ruppioides Bentham; Scirpus submersus C. Wright; Websteria limnophila S. H. Wright; W. submersa (C. Wright) Britton

Culms: primary ones pale green, 175 cm × 0.6 mm; stems green, 10 cm × 0.05 mm. Leaves: sheaths pale brown or red-brown, 7–10 mm. Spikelets: scales pale brown to green with red or purple marks, midvein colorless or green, lanceolate, 5–12 × 0.5–1.6 mm, margins scarious. Achenes pale brown to red-brown, ellipsoid, 2 × 1.2–1.5 mm; beak 1.4–2 × 0.2–0.3 mm.

Fruiting fall. Lakes; 0–50 m; Fla., Ga.; West Indies; Central America; South America; Asia (India, Malesia, Sri Lanka); Africa (including Madagascar); n Australia.

Sterile aquatic specimens of several species of Eleocharis have been confused with Websteria confervoides. Sterile specimens of W. confervoides can be recognized, with some confidence, by their pale, relatively stout main stems with numerous, very slender green branches, the somewhat enlarged nodes, long (to 11 mm) bracts subtending branches, and the usually reddish abscission zone of the bracts. Correctly identified specimens have been seen only from Florida and Georgia.