Eleocharis rostellata |
Eleocharis ovata |
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beak spike-rush, beak spikesedge, walking sedge, walking spikerush |
ovate spike-rush, ovoid spike-rush, ovoid spikesedge, éléocharide ovale |
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Habit | Plants densely tufted, mat-forming by means of rooting culm tips. | |
Culms | 1.5–3 times as wide as thick, 20–100 cm × 0.35–2 mm, firm to hard, wiry, with to 8 subacute ribs, rarely nearly smooth; some culms arching or decumbent and rooting at tips. |
2–35 cm × 0.3–1 mm. |
Leaves | distal leaf sheaths not splitting abaxially, proximally dark red to brown, apex usually reddish. |
apex of distal leaf sheath obtuse to acute, tooth to 0.2 mm. |
Spikelets | ovoid, 5–17 × 2.5–5 mm, apex acute; spikelets on stolons rudimentary, non-flowering, proliferous when rooting; proximal scale empty, amplexicaulous, ovate, 2–4 mm; subproximal scale with flower; floral scales 20–40, 2–3 per mm of rachilla, stramineous to medium brown, midrib region paler, ovate, 3.5–6 × 2–3 mm, membranous to cartilaginous, apex entire, rounded to subacute. |
ovoid, 2–8 × 2–4 mm, apex acute (to blunt); floral scales 25–100+, ca. 10 per mm of rachilla, orange-brown, rarely stramineous, ovate, 1.5–2 × 1 mm, midribs often keeled in distal part of spikelet, apex rounded to subacute. |
Flowers | perianth bristles brown, equaling achene or tubercle, densely spinulose; anthers brown, 2–2.4 mm. |
perianth bristles present, rarely absent, (5–)6–7, brown, fairly slender, exceeding tubercle; stamens 2(–3); anthers brown, 0.3 mm; styles 2-fid or some 3-fid. |
Achenes | often very variable within one plant, ovoid to obovoid or obpyriform, 1.5–2.5 × 1–1.2 mm, beak to 1 × 0.6 mm. |
0.75–1 × 0.6–0.85 mm. |
Tubercles | when present pale to dark brown, pyramidal, to 0.5 × 0.3 mm. |
deltoid, 0.3–0.5 × 0.3–0.5 mm, 3/5 of to as high as wide, 1/3–2/3 as high and 1/2–3/4 as wide as achene. |
2n | = 10. |
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Eleocharis rostellata |
Eleocharis ovata |
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Phenology | Fruiting late spring in south, summer–fall in north. | Fruiting summer–fall. |
Habitat | Very wet calcareous or brackish fens, springs, shores | Fresh, often drying shores, lake and stream beds, bogs, tidal estuaries, disturbed places |
Elevation | 50–2400 m (200–7900 ft) | 10–700 m (East), 1500–2000 m (Arizona) (0–2300 ft (East), 4900–6600 ft (Arizona)) |
Distribution |
AZ; CA; CT; DE; FL; ID; IL; IN; KS; LA; MA; MD; ME; MI; MN; MT; NC; NE; NJ; NM; NV; NY; OH; OK; PA; RI; SC; SD; TX; UT; VA; WA; WI; WY; BC; NS; ON; Mexico; West Indies (Cuba, Haiti, Puerto Rico)
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AZ; CT; IA; IL; IN; KY; MA; ME; MI; MN; MO; NH; NJ; NY; OH; OK; OR; PA; VA; VT; WA; WI; WV; AB; BC; NB; NL; NS; ON; PE; QC; Eurasia
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Discussion | Eleocharis rostellata is highly competitive, often forming large monospecific colonies. The South American E. platypus C. B. Clarke is often treated as a synonym of E. rostellata. Eleocharis rostellata superfically closely resembles E. suksdorfiana in its culms, spikelets, and achenes, but differs in the absence of creeping rhizomes, presence of stoloniferous culms, absence of a flower in the proximal scale, and achene surface details. The collection of E. rostellata I have seen from Miami-Dade County, Florida, is from 1877. I have not seen vouchers for Archuleta County, Colorado, by H. D. Harrington (1954), or for the localities in Montana and South Carolina, which are based on the map in H. K. Svenson (1934). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Although Eleocharis ovata has often been confused with E. obtusa, B. M. H. Larson and P. M. Catling (1996) showed that these species may be distinguished by non-overlapping widths of the tubercles, at least in Canada. The records of E. ovata in New Brunswick, Newfoundland, Nova Scotia, and Prince Edward Island are based on B. M. H. Larson and P. M. Catling (1996) and the records in Illinois, Indiana, Missouri, Montana, New Jersey, Oregon, and Washington are based on D. M. Hines (1975). Eleocharis ovata probably also occurs in Manitoba and Saskatchewan. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 90. | FNA vol. 23, p. 103. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Rostellatae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae |
Sibling taxa | ||
Synonyms | Scirpus rostellatus | Scirpus ovatus, E. obtusa var. ovata, E. ovata var. heuseri |
Name authority | (Torrey) Torrey: Fl. New York 2: 347. (1843) | (Roth) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817) |
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