Eleocharis uniglumis |
Eleocharis montana |
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creeping spike-rush, one-glumed spikesedge, onescale spikerush, slender spike-rush, éléocharide unigume |
mountain spikerush |
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Habit | Plants perennial, mat-forming; rhizomes evident, long, 0.3–1 mm thick, soft to firm, cortex often fugaceous, longer internodes 10–25 mm, scales fugaceous, 5–6 mm, membranous, not fibrous. | Plants perennial, densely tufted or mat-forming; rhizomes mostly hidden by culms and roots, fairly long, 3 mm thick, hard, cortex persistent, longer internodes to 3 mm, scales persistent, ca. 8 mm, membranous, slightly fibrous. |
Culms | terete, often with some blunt ridges when dry, (5–)10–60 cm × 0.2–1.5 mm, firm, internally spongy. |
terete, when dry with few to many blunt ridges, 10–70 cm × 0.5–2 mm, soft to firm, internally hollow with complete transverse septa 2–5 mm apart, usually evident externally except in narrowest culms. |
Leaves | distal leaf sheaths persistent, not splitting, proximally red, distally stramineous to green, often callose, thinly papery to thickly membranous, apex often dark red-brown, obtuse to subacute, tooth absent. |
distal leaf sheaths persistent, not splitting, proximally dark red, distally green or brown, slightly callose, papery, apex obtuse, tooth present, 0.3–1 mm. |
Spikelets | ovoid to lanceoloid, 5–10 × 2–3(–4) mm, apex acute; proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales often spreading in fruit, 10–20, 3–4 per mm of rachilla, brown to often red-brown, midrib regions mostly stramineous to green, broadly ovate, 3–4 × 1.8–2.5 mm, entire, apex acute to obtuse, often some carinate in distal part of spikelet. |
ovoid, 6–21 × 3–4 mm, apex acute to obtuse; proximal scale amplexicaulous, entire; subproximal scale empty or with flower; floral scales appressed in fruit, 100–500+, (15–)30–40 per mm of rachilla, medium brown to colorless, midrib regions greenish to colorless, ovate, 1.5–2.5 × 1–1.5 mm, entire, apex rounded to subacute, carinate in distal part of spikelet. |
Flowers | perianth bristles 0–4(–5), light brown to stramineous, stout, usually unequal, rudimentary to equaling achene; stamens 3; anthers dark yellow to stramineous, 1.2–2 mm; styles 2-fid. |
perianth bristles 6–8, pale brown, medium stout, from less than 1/2 achene length to sometimes slightly exceeding tubercle, retrorsely spinulose; stamens 1; anthers dark yellow to brown, 0.6–1 mm; styles 3-fid or some 2-fid. |
Achenes | not persistent, dark yellow or medium or dark brown, ellipsoid, obovoid, or obpyriform, biconvex, angles obscure, 1.3–1.8 × 1–1.4 mm, apex rounded, neck absent or short, smooth at 30X, or sometimes finely rugulose at 10–20X with 20 or more horizontal ridges in vertical series. |
falling with scales, dark green or medium brown, obovoid to obpyriform, biconvex or sometimes some compressedtrigonous in same spikelet, lateral angles prominent, abaxial angle absent or evident, not prominent, 0.8–1.1 × 0.7–0.8 mm, neck short or absent, finely cancellate at 10–20X, sometimes finely rugulose, with 15 horizontal ridges in vertical series. |
Tubercles | brown to whitish, pyramidal, much higher than wide to slightly depressed, sometimes spongy and with vertical rows of depressions, 0.4–0.8 × 0.3–0.8 mm. |
brown, pyramidal, mostly depressed, 0.2–0.35 × 0.2–0.4 mm. |
Eleocharis uniglumis |
Eleocharis montana |
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Phenology | Fruiting summer. | Fruiting winter–fall. |
Habitat | Mostly coastal, brackish (to fresh?) shores, marshes | Fresh temporary or artificial ponds, ditches, burned savannas, swamp margins |
Elevation | 0–2300 m (0–7500 ft) | 20–90[–2800] m (100–300[–9200] ft) |
Distribution |
CO; DE; MA; ME; NC; ND; NE; NH; NJ; NM; NV; NY; RI; SD; UT; VA; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; Eurasia
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AL; AZ; FL; GA; LA; TX; Mexico; Central America; South America; West Indies |
Discussion | Plants treated as Eleocharis uniglumis fall within the large morphologic variation of Eurasian E. uniglumis. Two subspecies and 3 varieties were recognized for northern Europe (S.-O. Strandhede 1966), and five species that were recognized by I. D. Zinserling (1935) were placed in synonymy under E. uniglumis (S.-O. Strandhede 1966). Recognition of infraspecific taxa within North American E. uniglumis is premature. Plants commonly called E. halophila or E. uniglumis var. halophila, found mostly in Atlantic Coastal brackish habitats, have floral scales that are usually narrower and more densely placed on the rachilla than plants usually called E. uniglumis, which are found mostly in the interior; some plants are intermediate in expression of these characters. The achene and tubercle shape characters used by M. L. Fernald (1950) to distinguish E. uniglumis from E. halophila are not valid. In North America, E. uniglumis is difficult to separate from E. erythropoda and E. kamtschatica, in both of which the spikelets have only the proximal scale without a flower (empty) and the proximal scale completely amplexicaulous. Eleocharis uniglumis differs from E. erythropoda only in its broader floral scales, which are less densely placed on the rachilla; it differs from E. kamtschatica only in its smaller tubercles. It is also difficult to separate from some specimens of E. macrostachya in which the spikelets have proximal scales that are sometimes completely amplexicaulous; such plants differ from E. uniglumis only in the absence of a flower in the axil of the subproximal scale of some of the spikelets. I have not seen voucher specimens for the chromosome numbers of 2n = 27 and 28 reported by S.-O. Strandhede (1967) from Massachusetts and Nebraska, which are lower than the 2n = (44–)46(47–88) reported for Europe (S.-O. Strandhede 1965). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The taxonomy of the septate-culmed species here treated as Eleocharis montana and E. ravenelii should be evaluated. According to H. K. Svenson (1957), the type of E. montana from near Bogotá, Colombia, is the mountain extreme of the species; it has swollen culms with no visible septation. Specimens from Acadia and St. Landry parishes, Louisiana, are intermediate between Eleocharis montana and E. montevidensis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 76. | FNA vol. 23, p. 79. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis |
Sibling taxa | ||
Synonyms | Scirpus uniglumis, E. halophila, E. uniglumis var. halophila | Scirpus montanus, E. montana var. nodulosa, E. nodulosa |
Name authority | (Link) Schultes: Mant. 2: 88. (1824) | (Kunth) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 153. (1817) |
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