Eleocharis microcarpa |
Eleocharis erythropoda |
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small-fruit spikesedge, smallfruit spikerush |
bald spike-rush, red-footed spikesedge, red-stem spikerush, redfoot spike-rush, spikesedge, éléocharide à tiges rouges |
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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, mat-forming; rhizomes evident, long, 0.5–1.5 mm thick, soft to firm, cortex often breaking loose, longer internodes 5–30 mm, scales often fugaceous, 4–8 mm, membranous, not fibrous. | ||||
Culms | often ascending or arching, quadrangular or broadly elliptic, 2–40 cm × 0.1–0.4(–0.6) mm, soft. |
terete, often with 8–12 blunt ridges when dry, 8–80 cm × 0.3–1.4 mm, firm to soft, internally spongy. |
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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, not splitting, proximally red (to stramineous), distally green to stramineous, usually inflated, often callose, membranous to papery, apex often red-brown, broadly obtuse to subacute, tooth sometimes present, to 0.1 mm. |
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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 to lanceoloid or nearly cylindric, 3–18 × 2–3(–4) mm, apex acute (to obtuse); proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales often spreading in fruit, 15–50, 4–5 per mm of rachilla, medium brown to sometimes red-brown, midrib regions mostly stramineous to green, in proximal part of spikelet ovate, apex rounded, in distal part lanceolate, apex entire, acute, 2–3.5 × 1.5–1.7 mm, mostly carinate. |
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Flowers | perianth bristles present or sometimes apparently absent; stamens 3; anthers 0.15–0.35; styles 3-fid. |
perianth bristles 4 or absent, light brown to stramineous, stout, usually equal, equaling achene to slightly exceeding tubercle; stamens 3; anthers dark yellow to stramineous, 1–1.8 mm, apiculate; styles 2-fid. |
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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. |
not persistent, dark yellow, stramineous, or dark brown, obovoid to obpyriform, biconvex, angles obscure, 0.9–1.6 × 0.7–1.2 mm, apex rounded, neck absent to long, smooth at 30X, or sometimes finely rugulose at 10–30X with 20 or more horizontal ridges in a vertical series. |
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Tubercles | green or pale brown to red-brown, trigonous. |
brown to whitish, pyramidal, much higher than wide to, lower than wide, 0.35–0.65 × 0.2–0.6 mm. |
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2n | = 16, 18, 19, 20. |
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Eleocharis microcarpa |
Eleocharis erythropoda |
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Phenology | Fruiting summer. | |||||
Habitat | Non-calcareous or calcareous fresh or brackish shores, marshes, meadows, fens, disturbed places | |||||
Elevation | 0–2300 m (0–7500 ft) | |||||
Distribution |
AL; FL; GA; IN; LA; MA; MD; MI; MS; NC; NJ; PA; SC; TN; TX; VA; West Indies
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AK; AR; AZ; CO; CT; DE; IA; ID; IL; IN; KS; KY; MA; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NT; ON; QC; SK
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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.) |
Eleocharis erythropoda is extremely variable. Intermediates with E. palustris variant b are common in the region of sympatry in the East, and with E. macrostachya variant b in the West, and E. erythropoda is sometimes difficult to distinguish from E. uniglumis. Eleocharis calva Torrey is an invalid name. (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. 75. | ||||
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Scirpus glaucus | |||||
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 312. (1836) | Steudel: Syn. Pl. Glumac. 2: 76. (1855) | ||||
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