Eleocharis atropurpurea |
Eleocharis albida |
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purple spike-rush |
white spikerush |
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Habit | Plants tufted, without creeping rhizomes. | Plants perennial; rhizomes soft, longer internodes 2–4 cm, cortex loose, scales fugaceous, 6 mm, thinly membranous and translucent. |
Culms | 2–12(–19) cm × 0.2–0.4 mm. |
not rooting at tips, terete, 10–40 cm, soft to firm, smooth. |
Leaves | distal leaf sheaths firm, distally tightly sheathing, apex acute. |
distal leaf sheaths proximally brownish or sometimes reddish, distally stramineous to green. |
Spikelets | ovoid to ellipsoid, 2–6(–8) × 1–2.5 mm, apex acute; proximal scale with or without flower, not amplexicaulous; floral scales to 100, 15–19 per mm of rachilla, often loosely appressed, dark red-brown to stramineous, ovate to elliptic, 0.6–1.3 × 0.3–0.7 mm, membranous, apex rounded to acute. |
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. |
Flowers | perianth bristles (0–)4–6, typically 4, colorless to whitish, vestigial to 1/2 as long as achene, smooth or spinuliferous; styles 2-fid. |
perianth bristles (5–)6(–8), brown, stout, the longer equaling achene or tubercle, retrorsely spinulose; stamens 3; anthers brown, 1 mm. |
Achenes | black, obovoid, biconvex, 0.3–0.5 × 0.3–0.4 mm, apex often constricted proximal to tubercle, smooth at 40X. |
falling with scales, obovoid, angles keeled, 0.8–1 × 0.7–0.8 mm, apex with short neck. |
Tubercles | stramineous to whitish, umbonate to subconic, 0.1–0.2 × 0.1–0.2 mm, apex acute. |
whitish to brown, mammillate to pyramidal, 0.2–0.3 × 0.3–0.35 mm, 1/3 or less as wide as achene. |
2n | = 20. |
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Eleocharis atropurpurea |
Eleocharis albida |
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Phenology | Fruiting summer–fall (Jun–Sep). | Fruiting summer. |
Habitat | Canal banks, hammocks, irrigation ditches, lake and pond margins, maritime shores, rice fields | Coastal saltmarsh edges, sloughs, beaches, dune depressions, ditches |
Elevation | 0–1800 m (0–5900 ft) | 0 m (0 ft) |
Distribution |
AL; CA; FL; GA; IA; KS; LA; MI; MO; NC; NE; NM; OK; SC; TX; WA; BC; Mexico; Central America; South America; West Indies; Europe (naturalized); Asia; Africa; Pacific Islands
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AL; FL; GA; LA; MD; MS; NC; NM; SC; TX; Mexico; Bermuda
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Discussion | Eleocharis atropurpurea has been reported from Colorado, Montana, and Virginia; I have not seen voucher specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 23, p. 102. | FNA vol. 23, p. 99. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Albidae |
Sibling taxa | ||
Synonyms | Scirpus atropurpureus | |
Name authority | (Retzius) J. Presl & C. Presl: in C. B. Presl, Reliq. Haenk. 1: 196. (1828) | Torrey: Ann. Lyceum Nat. Hist. New York. 3: 304. (1836) |
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