Eleocharis quinqueflora |
Eleocharis radicans |
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few-flower spike-rush, few-flower spikesedge, éléocharide à cinq fleurs |
creeping spikerush, radical fiber optic spikerush, root spikerush |
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Habit | Plants perennial; rhizomes 0.2–1 mm thick, scales persistent or fugaceous, 2–4(–7) mm, thinly membranous, not fibrous; resting buds often present on rhizomes or among culm bases, broadly to narrowly ovoid, 3–6(–10) × 2–5 mm; caudices absent, rarely present, soft or rarely hard, 0.5 mm thick. | Plants perennial, mat-forming; rhizomes 0.2–0.5 mm thick, longer internodes 5–10 mm, scales not evident. |
Culms | erect, not spirally twisted, not contracted near spikelet, when dry usually with several blunt to acute ridges and sulcate, subterete to slightly compressed, to 2 times wider than thick, 5–35 cm × 0.2–0.5(–1.2) mm, soft to hard; culm tufts often proximally bulbous (if bulbous then tunicated by papery-fibrous scales). |
obscurely to ca. 10-ribbed when dry, terete, 1–12 cm × 0.4–1 mm, very soft, spongy. |
Leaves | distal leaf sheaths stramineous to brown or reddish proximally, green to stramineous or brown distally, membranous to papery, apex often reddish, subtruncate to acute. |
distal leaf sheaths fugaceous, colorless, translucent, apex blunt. |
Spikelets | 3–8 × 1.5–4 mm; proximal scale with a flower, seldom empty, 2–5 mm, 1/2 or more as long as spikelet; floral scales 3–10 per spikelet, 2.5–6 × 1.5–2.5 mm. |
ovoid, 2–3 × 1–1.5 mm, apex acute; scales 5–15, 5–7 per mm of rachilla, colorless to stramineous, rarely slightly reddish, medially broadly greenish to colorless, faintly 3–5-veined, often ovate, membranous, fleshy; proximal scale 2–2.5 × 0.7 mm, other scales 1.5–2 × 0.7 mm, midrib obscure to slightly keeled, apex acute to rounded. |
Flowers | perianth bristles (0–)3–6, often unequal, rudimentary to equaling tubercle, stout to slender, spinules dense to apparently absent; anthers 1.5–2.7(–3.5) mm. |
perianth bristles equaling achene; anthers yellow to brown, 0.3–0.5 mm. |
Achenes | stramineous to medium brown or gray-brown, equilaterally trigonous to compressed-trigonous, rarely some biconvex, obpyriform (to obovoid), 1.6–2.3 × 0.7–1.3 mm, beak variable. |
brownish, angles plus longitudinal ridges ca. 7, narrowly obovoid, 2 times longer than wide, 0.75–0.9 × 0.35–0.4 mm, trabeculae ca. 50, distinct. |
Tubercles | rarely absent, 0.3–0.4 × 0.2–0.3 mm. |
brown, pyramidal, 0.15 × 0.15–0.2 mm. |
Eleocharis quinqueflora |
Eleocharis radicans |
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Phenology | Fruiting (spring–)summer. | Fruiting spring–winter (Apr–Dec). |
Habitat | Fens, wet meadows, seeps, springs, hot springs | Stream alluvium, lake margins, meadows, seeps, bogs |
Elevation | 0–3600 m (0–11800 ft) | 100–1400 Ariz., Calif., Fla., La., Mich., Okla., Tex., Va. |
Distribution |
AK; AZ; CA; CO; IA; ID; IL; IN; MA; ME; MI; MN; MT; NE; NH; NJ; NM; NV; NY; OH; OR; PA; UT; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; Greenland; Eurasia
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HI; n Mexico; West Indies; Central America (El Salvador); South America (Argentina, Chile)
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Discussion | The chromosome numbers for Eleocharis quinqueflora reported for North America (2n = 80) are in doubt because vouchers and other information are lacking. The often-cited n = 10 is probably erroneous. S.-O. Strandhede and R. M. T. Dahlgren (1968) gave 2n = 132 and 134 from Scandinavia. Recognition of infraspecific taxa within E. quinqueflora is premature pending a worldwide revision of subg. Zinserlingia. It has been reported from North Dakota, although I have not seen specimens. About five varieties and subspecies of E. quinqueflora have been described worldwide. Most specimens from eastern North America and some from the West can be placed in Eleocharis quinqueflora subsp. fernaldii (Svenson) Hultén, which is characterized by its small size (culms to 15 cm × 0.5 mm) and small bulbs. Specimens of E. quinqueflora from 2000–3600 m in California, which are atypical, especially in that the proximal scales of the spikelets do not subtend flowers, may deserve taxonomic recognition. Those plants are also small, with culms only to 15 cm × 0.5 mm; hard caudices are often present at the culm-tuft bases; small, narrowly ovoid bulbs are sometimes present; and perianth bristles are absent or rudimentary. Very few specimens of E. quinqueflora are intermediate with E. suksdorfiana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 114. | FNA vol. 23, p. 112. |
Parent taxa | Cyperaceae > Eleocharis > subg. Zinserlingia | Cyperaceae > Eleocharis > subg. Scirpidium |
Sibling taxa | ||
Synonyms | Scirpus quinqueflorus, E. fernaldii, E. pauciflora, E. pauciflora var. fernaldii, E. quinqueflora subsp. fernaldii | Scirpus radicans, E. acicularis var. radicans, E. lindheimeri |
Name authority | (Hartmann) O. Schwarz: Mitt. Thüring. Bot. Ges. 1: 89. (1949) | (Poiret) Kunth: Enum. Pl. 2: 142. (1837) |
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