Eleocharis microcarpa |
Eleocharis flavescens |
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small-fruit spikesedge, smallfruit spikerush |
pale spike-rush, wrinkle-sheath spike-rush, yellow spikerush, yellow spikesedge |
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Habit | Plants usually annual, tufted, sometimes mat-forming via proliferating and arching inflorescences (stoloniferous), sometimes entirely vegetative; rhizomes absent. | Plants with creeping rhizomes 0.5–1 mm thick. | ||||||||
Culms | often ascending or arching, quadrangular or broadly elliptic, 2–40 cm × 0.1–0.4(–0.6) mm, soft. |
3–42 cm × 0.3–0.6 mm. |
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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 often disintegrating, thinly membranous-translucent, inflated distally, often wrinkled, 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. |
ellipsoid, 1.5–9 × 1–3.5 mm, apex acute to acuminate; proximal scale without flower, not amplexicaulous; floral scales to 65, 5–7 per mm of rachilla, loosely appressed to appressed, elliptic, 1–3 × 0.4–1.6 mm, membranous, apex 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 (0–)5–8, typically 7, white to stramineous, spinules dense to few; styles 2-fid, rarely 3-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. |
stramineous to green or dark brown, biconvex, rarely trigonous, obovoid to obpryiform, 0.4–1.1 × 0.3–0.8 mm, very finely reticulate at 40X. |
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Tubercles | green or pale brown to red-brown, trigonous. |
whitish to stramineous or green, 0.2–0.7 × 0.2–0.4 mm, apex acute to acuminate. |
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Eleocharis microcarpa |
Eleocharis flavescens |
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Distribution |
AL; FL; GA; IN; LA; MA; MD; MI; MS; NC; NJ; PA; SC; TN; TX; VA; West Indies
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AL; AR; AZ; CA; CT; DE; FL; GA; ID; IL; IN; LA; MA; MD; ME; MI; MN; MS; MT; NC; NH; NJ; NY; OH; PA; RI; SC; TX; UT; VA; VT; WI; WY; NB; NS; ON; QC; South America; temperate North America; West Indies
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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.) |
Varieties 2 (2 in the flora). The varieties of Eleocharis flavescens are difficult to delimit, especially in the south, and identifications of some specimens to variety are problematic. (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. 100. | ||||||||
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Scirpus flavescens | |||||||||
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 312. (1836) | (Poiret) Urban: Symb. Antill. 4: 116. (1903) | ||||||||
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