Eleocharis baldwinii |
Eleocharis flavescens |
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Baldwin's spike-rush |
pale spike-rush, wrinkle-sheath spike-rush, yellow spikerush, yellow spikesedge |
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Habit | Plants annual(?), often mat-forming, often stoloniferous, sometimes entirely vegetative; rhizomes absent. | Plants with creeping rhizomes 0.5–1 mm thick. | ||||
Culms | often arching, sometimes spotted or streaked red-brown, quadrangular or broadly elliptic, sulcate or not, 0.5–25(–30) cm × 0.1–0.4 mm, soft. |
3–42 cm × 0.3–0.6 mm. |
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Leaves | distal leaf sheaths persistent or disintegrating, stramineous, green, red-brown, or spotted or streaked red-brown, membranous, translucent, apex obtuse or acute. |
distal leaf sheaths often disintegrating, thinly membranous-translucent, inflated distally, often wrinkled, apex blunt. |
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Spikelets | basal spikelets usually present, pistillate; often proliferous, ovoid, ellipsoid, or linear, clearly laterally compressed, 2.3–6.9 × 0.5–2 mm, apex acute, proximal scale empty, amplexicaulous, similar to floral scales (midribs sometimes more prominent and sometimes slightly prolonged beyond lamina); subproximal scale with a flower; floral scales clearly distichous, 3–9, 3–4 per mm of rachilla, yellowish, pale brown, or red-brown, spotted, streaked, or mottled red-brown, narrowly ovate to oblong, (1.5–)2–5 × 0.4–0.6(–1.2) mm, membranous, apex rounded, obtuse or rarely acute, midribs keeled. |
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 3–7, incurved, colorless, white, or red-brown, shorter than or equaling achene; spinules sparse, retrorse, sharply acute; stamens 3; anthers 1.4–2.2 mm; 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 or greenish, spotted dark green, obovoid, trigonous, angles prominent, 0.6–0.9 × 0.4–0.6 mm, apex constricted proximal to tubercle, smooth to finely cancellate at 10–20X. |
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 | pale to red-brown, pyramidal, trigonous, 0.2–0.3(–0.4) × 0.2–0.5 mm. |
whitish to stramineous or green, 0.2–0.7 × 0.2–0.4 mm, apex acute to acuminate. |
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Eleocharis baldwinii |
Eleocharis flavescens |
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Phenology | Fruiting early spring–winter. | |||||
Habitat | Freshwater to moist terrestrial sites, pine savannas, cypress ponds, lakeshores | |||||
Elevation | 0–60 m (0–200 ft) | |||||
Distribution |
AL; AR; FL; GA; LA; MS; NC; SC; TX
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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 | Coarse plants of Eleocharis baldwinii usually bear more achenes per spikelet, dark colored achenes, culms gray-green when dried, and yellowish sheaths. Finer plants often bear few achenes per spikelet, whitish achenes, culms that are mid green when dried, and reddish sheaths. Achene color may relate to maturity, with darker achenes being fully mature. Although these variants appear to intergrade, they may be recognizable taxonomically. The longer floral scales in the spikelet are usually 3.5– 5 mm. We have not seen vouchers to verify the report of Eleocharis baldwinii from Virginia. (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. 98. | 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 | Chaetocyperus baldwinii | Scirpus flavescens | ||||
Name authority | (Torrey) Chapman: Fl. South. U.S., 519. (1860) | (Poiret) Urban: Symb. Antill. 4: 116. (1903) | ||||
Web links |
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