Eleocharis microcarpa |
Eleocharis reverchonii |
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small-fruit spikesedge, smallfruit spikerush |
Reverchon's spikerush |
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Habit | Plants usually annual, tufted, sometimes mat-forming via proliferating and arching inflorescences (stoloniferous), sometimes entirely vegetative; rhizomes absent. | Plants perennial; rhizomes sometimes not evident, 0.3–0.5 mm thick, internodes 3–11 mm, scales not evident. | ||||
Culms | often ascending or arching, quadrangular or broadly elliptic, 2–40 cm × 0.1–0.4(–0.6) mm, soft. |
sometimes arched, smooth or obscurely 4- or 5-angled or -ridged, terete or slightly compressed, 6–25 cm × 0.15–0.3 mm, soft to firm. |
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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. |
distal leaf sheaths persistent, red proximally, colorless distally, closely sheathing, apex blunt. |
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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. |
ovoid, 2–6 × 1–2 mm, apex acute; scales 5–15, 5 per mm of rachilla, bright red-brown, midrib region green to stramineous, ovate, 1.5–1.7 × 1 mm, midrib keeled to obscure, apex blunt to acute. |
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Flowers | perianth bristles present or sometimes apparently absent; stamens 3; anthers 0.15–0.35; styles 3-fid. |
perianth bristles absent; anthers 0.5–1 × 0.2 mm. |
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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. |
with angles plus longitudinal ridges ca. 8–9, obscure to rather prominent, obovoid to obpyriform, much less than 2 times longer than wide, 0.55–0.6 × 0.3–0.4 mm, trabeculae 20–30, rather obscure and crowded. |
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Tubercles | green or pale brown to red-brown, trigonous. |
brownish to whitish, pyramidal to depressed, 0.1–0.15 × 0.1–0.2 mm. |
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Eleocharis microcarpa |
Eleocharis reverchonii |
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Phenology | Fruiting late winter–spring (Feb–Apr). | |||||
Habitat | Wet soil of ponds, marshes, grasslands, ditches | |||||
Elevation | 10–200 m (0–700 ft) | |||||
Distribution |
AL; FL; GA; IN; LA; MA; MD; MI; MS; NC; NJ; PA; SC; TN; TX; VA; West Indies
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TX |
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Discussion | 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Eleocharis reverchonii perhaps should be treated as a variety or subspecies of E. acicularis. One collection (three sheets at KSC) from Calhoun county in southeastern Texas is apparently the only known example within E. subg. Scirpidium with proliferous spikelets. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 23, p. 95. | FNA vol. 23, p. 110. | ||||
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae | Cyperaceae > Eleocharis > subg. Scirpidium | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 312. (1836) | Svenson: Rhodora 31: 203, fig. 27. (1929) | ||||
Web links |