Eleocharis melanocarpa |
Eleocharis erythropoda |
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black-fruit spike-rush, black-fruit spikesedge |
bald spike-rush, red-footed spikesedge, red-stem spikerush, redfoot spike-rush, spikesedge, éléocharide à tiges rouges |
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Habit | 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 | to 2 times wider than thick, 35–60(–70) cm × 0.5–1.3 mm, hard, usually with to 10 blunt ribs, at 20X often finely ridged and minutely granular. |
terete, often with 8–12 blunt ridges when dry, 8–80 cm × 0.3–1.4 mm, firm to soft, internally spongy. |
Leaves | distal leaf sheaths brown to reddish. |
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. |
Spikelets | 3–12 × 3–4 mm; proximal scale amplexicaulous, 3.5–4 mm, midrib region very broad and fleshy, apex entire; subproximal scale with a flower; floral scales 30–40, 8–10 per mm of rachilla, orange-brown to stramineous, midrib region stramineous, broadly ovate, papery or sometimes membranous, 3–4 × 2 mm, apex entire, rounded. |
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. |
Flowers | perianth bristles present, sometimes rudimentary, brown, length variable, obscurely retrorsely spinulose; anthers brown, 1.7–2.2 mm. |
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. |
Achenes | subdeltoid in outline, sometimes broadly obpyriform, equilaterally trigonous, angles prominent, 0.9–1.2 × 0.7–1.1 mm, apex truncate. |
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. |
Tubercles | sessile, depressed-pyramidal, often apiculate, as wide as achene, 0.3–0.5 × 0.7–1.1 mm. |
brown to whitish, pyramidal, much higher than wide to, lower than wide, 0.35–0.65 × 0.2–0.6 mm. |
2n | = 16, 18, 19, 20. |
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Eleocharis melanocarpa |
Eleocharis erythropoda |
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Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Fresh, oligotrophic, acid, sandy or peaty, often drying shores, ponds, ditches | Non-calcareous or calcareous fresh or brackish shores, marshes, meadows, fens, disturbed places |
Elevation | 10–300 m (0–1000 ft) | 0–2300 m (0–7500 ft) |
Distribution |
AL; FL; GA; IN; MA; MI; NC; NY; RI; SC; TX; VA
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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 | Eleocharis melanocarpa is reported from Rhode Island; I have not seen a voucher specimen. (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.) |
Source | FNA vol. 23, p. 89. | FNA vol. 23, p. 75. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Melanocarpae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis |
Sibling taxa | ||
Synonyms | Scirpus glaucus | |
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 311. (1836) | Steudel: Syn. Pl. Glumac. 2: 76. (1855) |
Web links |
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