Eleocharis cellulosa |
Eleocharis tuberculosa |
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Gulf Coast spikerush, Gulfcoast spikesedge |
cone-cup spikerush, long-tubercled spikerush, long-tubercled spikesedge |
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Habit | Plants perennial; rhizomes 1–4 mm thick, soft to hard, longer internodes 3–7.5 cm, scales 5 mm, tubers absent. | 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 | 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. |
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 persistent, membranous, apex acute to acuminate, often prolonged into a slender awn to 4 mm. |
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 | 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. |
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 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. |
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 | 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. |
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 | dark brown, lamelliform to pyramidal, 0.1–0.5 × 0.2–0.5 mm. |
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 cellulosa |
Eleocharis tuberculosa |
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Phenology | Fruiting late spring–winter. | Fruiting spring (in south)–fall. |
Habitat | Brackish to saline marshes, shores, ditches, mostly coastal, often abundant or dominant | Wet soil, freshwater, ponds, lakeshores, streams, meadows, pine woods, grasslands, disturbed places, bogs |
Elevation | 0 (Florida)–600 (Arkansas, Texas) m (0 (Florida)–2000 (Arkansas, Texas) ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; AR; FL; GA; MS; NC; SC; TX; Mexico; West Indies; Central America (Nicaragua)
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AL; AR; FL; GA; LA; MA; MS; NC; NJ; SC; TN; TX; NS
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Discussion | 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.) |
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Source | FNA vol. 23, p. 118. | FNA vol. 23, p. 92. |
Parent taxa | Cyperaceae > Eleocharis > subg. Limnochloa | 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: 298. (1836) | (Michaux) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817) |
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