Eleocharis albida |
Eleocharis tuberculosa |
|
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white spikerush |
cone-cup spikerush, long-tubercled spikerush, long-tubercled spikesedge |
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Habit | Plants perennial; rhizomes soft, longer internodes 2–4 cm, cortex loose, scales fugaceous, 6 mm, thinly membranous and translucent. | Plants perennial, forming dense clumps, not stoloniferous. |
Rhizomes | present or not, caudexlike, ascending, 1 mm thick; internodes and scales hidden by crowded culms, not evident. |
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Culms | not rooting at tips, terete, 10–40 cm, soft to firm, smooth. |
elliptic or sometimes circular, with several rounded ridges and sulcate when dry, 15–75 cm × 0.3(–1.5) mm, firm, minutely granular at 10X. |
Leaves | distal leaf sheaths proximally brownish or sometimes reddish, distally stramineous to green. |
distal leaf sheaths persistent; stramineous to green, often minutely red-spotted, papery to membranous, apex subacute to narrowly acute, often with tooth-like callus. |
Spikelets | ovoid to oblong-subcylindric, 4–12 × 2–3.5 mm, apex acute to rounded; proximal scale empty, clasping 1/2 of culm, like floral scales; subproximal 1 or 2 scales often empty; floral scales 20–100, 10 per mm of rachilla, entirely stramineous or sometimes red-brown, ovate, (1.5–)2–2.5 × 1.5 mm, apex broadly rounded, entire. |
basal spikelets absent; never proliferous, ovoid, terete, 5–15 × 2.5–4 mm, apex acute; proximal scale empty, deciduous, clasping 1/2 of culm, similar to floral scales; subproximal scale often empty; floral scales spiraled, 10–30, 5–6 per mm of rachilla, pale orange-brown, midribs green, broadly ovate, 2.5–4 × 1.5–2.5 mm, central area and often flanks papery to cartilaginous (or membranous), midrib evident, apex broadly rounded to obtuse. |
Flowers | perianth bristles (5–)6(–8), brown, stout, the longer equaling achene or tubercle, retrorsely spinulose; stamens 3; anthers brown, 1 mm. |
perianth bristles 5–6, bright brown, stout, slightly shorter than to equaling tubercle; spinules rarely absent, dense, variably from divaricate to antrorse, very short, and blunt to acute, to often much longer and retrorse, sharply acute; stamens 2–3; anthers 0.5–1 mm; styles 3-fid. |
Achenes | falling with scales, obovoid, angles keeled, 0.8–1 × 0.7–0.8 mm, apex with short neck. |
medium brown, obovoid to obpyriform, compressed (often obscurely) trigonous, angles evident, 0.9–1.7 × 0.8–2 mm; apex often constricted proximal to tubercle, very coarsely cancellate at 10X, each face with 8–10 longitudinal rows of large depressions. |
Tubercles | whitish to brown, mammillate to pyramidal, 0.2–0.3 × 0.3–0.35 mm, 1/3 or less as wide as achene. |
bone-white to pale orange-brown, often red-spotted, subpyramidal, cross section plano-convex, 0.9–1.7(–2.4) × 0.7–1.2–2(–2.2) mm, at least as high and wide as achene, spongy, apex rounded, often with an abaxial acute projection. |
Eleocharis albida |
Eleocharis tuberculosa |
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Phenology | Fruiting summer. | Fruiting spring (in south)–fall. |
Habitat | Coastal saltmarsh edges, sloughs, beaches, dune depressions, ditches | Wet soil, freshwater, ponds, lakeshores, streams, meadows, pine woods, grasslands, disturbed places, bogs |
Elevation | 0 m (0 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; FL; GA; LA; MD; MS; NC; NM; SC; TX; Mexico; Bermuda
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AL; AR; FL; GA; LA; MA; MS; NC; NJ; SC; TN; TX; NS
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Discussion | In most spikelets, the bright brown stigmas contrast strikingly with the stramineous floral scales. We have not seen vouchers for H. K. Svenson’s (1937) reports of Eleocharis albida from Virginia. The collections we have seen from Maryland are from the 1800s. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eleocharis tuberculosa evidently is closely related to E. tortilis, from which it differs in its larger tubercles, culms that are always elliptic in cross section, and perianth bristle spinules that are often divaricate to antrorse and often blunt. The specimens of E. tuberculosa from throughout its range which are like E. tortilis in having retrorsely spinulose perianth bristles have been named E. tuberculosa forma retrorsa Svenson (type from Massachusetts). Plants from Nova Scotia with nearly smooth bristles have been named E. tuberculosa var. pubnicoensis Fernald and E. tuberculosa forma pubnicoensis (Fernald) Svenson. We have not seen voucher specimens for literature reports of Eleocharis tuberculosa from Connecticut, Delaware, Maine, Maryland, New Hampshire, New York, Pennsylvania, Rhode Island, or Virginia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 99. | FNA vol. 23, p. 92. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Albidae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae |
Sibling taxa | ||
Synonyms | Scirpus tuberculosus, E. tuberculosa var. pubnicoensis | |
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York. 3: 304. (1836) | (Michaux) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817) |
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