Eleocharis montevidensis |
Eleocharis cellulosa |
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Montevideo spike rush, sand spikerush |
Gulf Coast spikerush, Gulfcoast spikesedge |
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Habit | Plants perennial, mat-forming; rhizomes evident, long, 0.7–2 mm thick, firm, cortex persistent, longer internodes 1–2 cm, scales often fugaceous, 6–8 mm, membranous, not fibrous. | Plants perennial; rhizomes 1–4 mm thick, soft to hard, longer internodes 3–7.5 cm, scales 5 mm, tubers absent. |
Culms | terete or cross section elliptic or rectangular, with 5–10 blunt ridges when dry, 25–50 cm × 0.5–1.2 mm, firm to hard, spongy. |
terete or obtusely trigonous, 30–80 cm × 1–5 mm, soft to hard, not septate-nodulose, internally spongy, transverse septa incomplete; plants never forming filiform, flaccid culms. |
Leaves | distal leaf sheaths persistent, not splitting, mostly proximally dark red, distally red to brown or green, thinly papery, apex usually red-brown, often callose, subtruncate to obtuse, tooth usually present on some or all culms, to 0.9 mm. |
distal leaf sheaths persistent, membranous, apex acute to acuminate, often prolonged into a slender awn to 4 mm. |
Spikelets | usually ovoid or ellipsoid to subcylindric, rarely lanceoloid, 4–12 × (1.5–)2–3 mm, apex rounded to acute; proximal scale amplexicaulous or clasping over 3/4 of culm, entire; subproximal scale empty or with flower; floral scales appressed in fruit, 30–100, 6–10 per mm of rachilla, orange-brown, midrib regions often greenish, oblong to ovate, 1.5–2.5 × 1–1.5 mm, apex entire, broadly rounded, sometimes acute in distal part of spikelet, usually horizontally wrinkled and recurved, often carinate in distal part of spikelet. |
not proliferous, 14–54 × 3–5.6 mm; rachilla joints without winglike remnants of floral scales; proximal scale empty, amplexicaulous, 2.5–4.9 mm; floral scales 40–180, 2–3 per mm of rachilla, stramineous to pale brown, flanks sometimes minutely dotted reddish, usually with pale to dark brown, reddish, or purplish submarginal band, obovate to suborbicular, widest in middle, 3.4–4.5(–6) × 3–4.8 mm, cartilaginous, membranous toward margins, margins broadly translucent, membranous, apex rounded. |
Flowers | perianth bristles 5–6(–7), stramineous to medium brown, stout, often unequal, much shorter than to equaling achene, rarely all rudimentary; stamens 3; anthers dark yellow to stramineous, 0.8–1.5 mm; styles 3-fid or some 2-fid. |
perianth bristles 6–7, medium brown to pale brown or reddish, slender, proximally slightly flattened, subequal to unequal, mostly exceeding achene, 2–3.4 mm, smooth or sometimes finely retrorsely spinulose; anthers reddish brown, 1.7–2.5 mm; styles 3-fid. |
Achenes | falling with scales, dark brown, obovoid to obpyriform, compressed trigonous, angles evident to obscure, 0.7–1 × 0.65–0.8 mm, neck absent to sometimes long, finely rugulose at 10–30X, over 20 horizontal ridges in vertical series, and/or minutely cancellate at 20–30X. |
brown, biconvex, obpyriform, 2.2–2.8 × 1.3–1.9 mm, markedly sculptured at 10–15X, each face with (17–)20–24 rows of isodiametric to slightly transversely elongated cells, apex narrowed to a stout, often pale, spongy region 0.8–1.1 mm wide at base, 1/2–3/4 of achene width. |
Tubercles | brown to whitish, pyramidal, as high as wide or sometimes greatly depressed, (0.1–)0.25–0.3 × 0.2–0.3 mm. |
dark brown, lamelliform to pyramidal, 0.1–0.5 × 0.2–0.5 mm. |
2n | = 20. |
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Eleocharis montevidensis |
Eleocharis cellulosa |
|
Phenology | Fruiting spring–fall. | Fruiting late spring–winter. |
Habitat | Wet soil, fresh ponds, lakes, streams, springs, seeps, marshes, ditches, grasslands | Brackish to saline marshes, shores, ditches, mostly coastal, often abundant or dominant |
Elevation | 0–2300 m (0–7500 ft) | 0 (Florida)–600 (Arkansas, Texas) m (0 (Florida)–2000 (Arkansas, Texas) ft) |
Distribution |
AL; AZ; CA; FL; KS; LA; MS; NC; NM; OK; SC; TX; Mexico; South America
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AL; AR; FL; GA; MS; NC; SC; TX; Mexico; West Indies; Central America (Nicaragua)
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Discussion | The name Eleocharis montana was long misapplied to E. montevidensis. The type of E. palmeri, recognized as a species (H. K. Svenson 1957), is indistinguishable from specimens of E. montevidensis. Eleocharis montevidensis is extremely variable; the broadly rounded, usually wrinkled and recurved floral scales are diagnostic. Achenes often fail to form. Eleocharis montevidensis is apparently closely related to E. parishii, in which the floral scales are less densely placed on the rachilla and acute to rounded, and the spikelets are narrowly lanceoloid to cylindric. In the absence of achenes and rhizomes, some specimens of E. montevidensis are easily mistaken for E. tricostata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 80. | FNA vol. 23, p. 118. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | Cyperaceae > Eleocharis > subg. Limnochloa |
Sibling taxa | ||
Synonyms | E. arenicola, E. montana subsp. montevidensis, E. palmeri | |
Name authority | Kunth: Enum. Pl. 2: 144. (1837) | Torrey: Ann. Lyceum Nat. Hist. New York 3: 298. (1836) |
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