Eleocharis atropurpurea |
Eleocharis melanocarpa |
|
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purple spike-rush |
black-fruit spike-rush, black-fruit spikesedge |
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Habit | Plants tufted, without creeping rhizomes. | |
Culms | 2–12(–19) cm × 0.2–0.4 mm. |
to 2 times wider than thick, 35–60(–70) cm × 0.5–1.3 mm, hard, usually with to 10 blunt ribs, at 20X often finely ridged and minutely granular. |
Leaves | distal leaf sheaths firm, distally tightly sheathing, apex acute. |
distal leaf sheaths brown to reddish. |
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. |
3–12 × 3–4 mm; proximal scale amplexicaulous, 3.5–4 mm, midrib region very broad and fleshy, apex entire; subproximal scale with a flower; floral scales 30–40, 8–10 per mm of rachilla, orange-brown to stramineous, midrib region stramineous, broadly ovate, papery or sometimes membranous, 3–4 × 2 mm, apex entire, rounded. |
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 present, sometimes rudimentary, brown, length variable, obscurely retrorsely spinulose; anthers brown, 1.7–2.2 mm. |
Achenes | black, obovoid, biconvex, 0.3–0.5 × 0.3–0.4 mm, apex often constricted proximal to tubercle, smooth at 40X. |
subdeltoid in outline, sometimes broadly obpyriform, equilaterally trigonous, angles prominent, 0.9–1.2 × 0.7–1.1 mm, apex truncate. |
Tubercles | stramineous to whitish, umbonate to subconic, 0.1–0.2 × 0.1–0.2 mm, apex acute. |
sessile, depressed-pyramidal, often apiculate, as wide as achene, 0.3–0.5 × 0.7–1.1 mm. |
2n | = 20. |
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Eleocharis atropurpurea |
Eleocharis melanocarpa |
|
Phenology | Fruiting summer–fall (Jun–Sep). | Fruiting summer. |
Habitat | Canal banks, hammocks, irrigation ditches, lake and pond margins, maritime shores, rice fields | Fresh, oligotrophic, acid, sandy or peaty, often drying shores, ponds, ditches |
Elevation | 0–1800 m (0–5900 ft) | 10–300 m (0–1000 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; IN; MA; MI; NC; NY; RI; SC; TX; VA
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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.) |
Eleocharis melanocarpa is reported from Rhode Island; I have not seen a voucher specimen. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 102. | FNA vol. 23, p. 89. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Melanocarpae |
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: 311. (1836) |
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