Eleocharis quinqueflora |
Eleocharis pachycarpa |
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few-flower spike-rush, few-flower spikesedge, éléocharide à cinq fleurs |
black sand spikerush, broad fruit 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, forming dense clumps, often stoloniferous. |
Rhizomes | present, caudexlike, mostly concealed by crowded culms, vertical or ascending, 2 mm thick; internodes very short, scales disintegrating to fibers, 4 mm, papery. |
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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). |
erect to ascending or arching, acutely quadrangular, deeply sulcate, 7–50 cm × 0.3–0.5 mm, smooth, firm. |
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 persistent, proximally brown or reddish, distally stramineous to green, thickly membranous, apex acute or subacute. |
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. |
basal spikelets absent; often proliferous, ovoid, terete, 3–10 × 2–3 mm, apex acute; proximal scale empty, amplexicaulous, similar to floral scales; subproximal scale with a flower; floral scales spiraled, 8–15, 4 per mm of rachilla, orange-brown, midrib region broadly stramineous or like flanks, ovate, 2–3 × 1.2–2 mm, membranous, midrib evident to prominent, 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 6 or fewer, stramineous, unequal, some or most equaling achene, spinules obscure, sparse, retrorse, sharply acute. |
Stamens | 3; anthers 1.2–1.5 mm. |
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Styles | 3-fid. |
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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. |
stramineous, broadly obpyriform, equilaterally trigonous, angles evident, blunt, 0.9–1.1 × 0.7–0.9 mm, apex nearly truncate, smooth or obscurely papillose or rugulose at 20X. |
Tubercles | rarely absent, 0.3–0.4 × 0.2–0.3 mm. |
stramineous, pyramidal, trigonous, usually acute, proximally trilobed, the lobes decurrent on achene, 0.5–0.9 × 0.7–0.9 mm. |
Eleocharis quinqueflora |
Eleocharis pachycarpa |
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Phenology | Fruiting (spring–)summer. | Fruiting late spring–summer. |
Habitat | Fens, wet meadows, seeps, springs, hot springs | Fresh shores, streambeds, groundwater seeps |
Elevation | 0–3600 m (0–11800 ft) | 100–1400 m (300–4600 ft) |
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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CA; NV; South America (Argentina, Chile) [Introduced in North America; introduced in Australia]
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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.) |
H. K. Svenson (1957) placed Eleocharis pachycarpa in ser. Sulcatae Svenson. Contrary to his statement that perianth bristles are often lacking, they are present in all of the specimens we have seen. Superficially similar to E. bolanderi, from which it may readily be distinguished by its oblique leaf sheath summits, 4-angled culms, pyramidal tubercles, and often proliferating spikelets. The earliest North American specimen we have seen was collected in 1919 in Tuolumne County, California. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 114. | FNA vol. 23, p. 91. |
Parent taxa | Cyperaceae > Eleocharis > subg. Zinserlingia | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae |
Sibling taxa | ||
Synonyms | Scirpus quinqueflorus, E. fernaldii, E. pauciflora, E. pauciflora var. fernaldii, E. quinqueflora subsp. fernaldii | |
Name authority | (Hartmann) O. Schwarz: Mitt. Thüring. Bot. Ges. 1: 89. (1949) | E. Desvaux: in C. Gay, Fl. Chil. 6: 174. (1853) |
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