Eleocharis microcarpa


Ann. Lyceum Nat. Hist. New York 3: 312. 1836.

Treatment appears in FNA Volume 23. Treatment on page 95. Mentioned on page 94.

Plants usually annual, tufted, sometimes mat-forming via proliferating and arching inflorescences (stoloniferous), sometimes entirely vegetative; rhizomes absent. Culms often ascending or arching, quadrangular or broadly elliptic, 2–40 cm × 0.1–0.4(–0.6) mm, soft. Leaves: distal leaf sheaths persistent or disintegrating, pale brown, green or red-brown, streaked or mottled red-brown or purple, translucent, membranous, apex narrowly acute. Spikelets: basal spikelets absent; often proliferous, ovoid to ellipsoid or lanceoloid, terete, 2–10.7 × 1–2 mm, apex acute; proximal scale empty, persistent, amplexicaulous, dissimilar to floral scales, often longer, often resembling an involucral bract, ovate to lanceolate, midrib markedly thickened and broad and often prolonged beyond lamina; subproximal scale with flower; floral scales spiraled, colorless, whitish, or pale brown, streaked or mottled red-brown or purple, midribs green and red-brown or green and purple, ovate to elliptic, 0.8–1.5 × 0.4–0.8 mm, membranous, midrib obscure to prominent. Flowers: perianth bristles present or sometimes apparently absent; stamens 3; anthers 0.15–0.35; styles 3-fid. Achenes whitish to olive or pale brown, sometimes spotted olive or red-brown, obovoid, trigonous (or subterete), angles prominent, 0.55–0.8 × 0.3–0.5 mm, apex constricted proximal to tubercle, smooth. Tubercles green or pale brown to red-brown, trigonous.


V23 134-distribution-map.jpg

Ala., Fla., Ga., Ind., La., Mass., Md., Mich., Miss., N.C., N.J., Pa., S.C., Tenn., Tex., Va., West Indies.


Varieties 2 (2 in the flora).

Specimens of Eleocharis brittonii and E. microcarpa without achenes are often difficult to distinguish. More detailed study of the four apparent entities across the two species is warranted.

Selected References



1 Perianth bristles 0.2–0.4 mm, shorter than achene; proximal scale of spikelets 0.4–0.5 mm wide. Eleocharis microcarpa var. microcarpa
1 Perianth bristles 0.6–1 mm, shorter than to equaling achene; proximal scale of spikelets 0.8–1 mm wide. Eleocharis microcarpa var. filiculmis
... more about "Eleocharis microcarpa"
Jeremy J. Bruhl +  and S. Galen Smith +
Torrey +
Ala. +, Fla. +, Ga. +, Ind. +, La. +, Mass. +, Md. +, Mich. +, Miss. +, N.C. +, N.J. +, Pa. +, S.C. +, Tenn. +, Tex. +, Va. +  and West Indies. +
Ann. Lyceum Nat. Hist. New York +
Illustrated +
Eleocharis +
Eleocharis microcarpa +
Eleocharis (sect. Eleocharis) ser. Tenuissimae +
species +