Eleocharis atropurpurea |
Eleocharis reverchonii |
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purple spike-rush |
Reverchon's spikerush |
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Habit | Plants tufted, without creeping rhizomes. | Plants perennial; rhizomes sometimes not evident, 0.3–0.5 mm thick, internodes 3–11 mm, scales not evident. |
Culms | 2–12(–19) cm × 0.2–0.4 mm. |
sometimes arched, smooth or obscurely 4- or 5-angled or -ridged, terete or slightly compressed, 6–25 cm × 0.15–0.3 mm, soft to firm. |
Leaves | distal leaf sheaths firm, distally tightly sheathing, apex acute. |
distal leaf sheaths persistent, red proximally, colorless distally, closely sheathing, apex blunt. |
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, 2–6 × 1–2 mm, apex acute; scales 5–15, 5 per mm of rachilla, bright red-brown, midrib region green to stramineous, ovate, 1.5–1.7 × 1 mm, midrib keeled to obscure, apex blunt to acute. |
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 absent; anthers 0.5–1 × 0.2 mm. |
Achenes | black, obovoid, biconvex, 0.3–0.5 × 0.3–0.4 mm, apex often constricted proximal to tubercle, smooth at 40X. |
with angles plus longitudinal ridges ca. 8–9, obscure to rather prominent, obovoid to obpyriform, much less than 2 times longer than wide, 0.55–0.6 × 0.3–0.4 mm, trabeculae 20–30, rather obscure and crowded. |
Tubercles | stramineous to whitish, umbonate to subconic, 0.1–0.2 × 0.1–0.2 mm, apex acute. |
brownish to whitish, pyramidal to depressed, 0.1–0.15 × 0.1–0.2 mm. |
2n | = 20. |
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Eleocharis atropurpurea |
Eleocharis reverchonii |
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Phenology | Fruiting summer–fall (Jun–Sep). | Fruiting late winter–spring (Feb–Apr). |
Habitat | Canal banks, hammocks, irrigation ditches, lake and pond margins, maritime shores, rice fields | Wet soil of ponds, marshes, grasslands, ditches |
Elevation | 0–1800 m (0–5900 ft) | 10–200 m (0–700 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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TX |
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.) |
Of conservation concern. Eleocharis reverchonii perhaps should be treated as a variety or subspecies of E. acicularis. One collection (three sheets at KSC) from Calhoun county in southeastern Texas is apparently the only known example within E. subg. Scirpidium with proliferous spikelets. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 102. | FNA vol. 23, p. 110. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Scirpidium |
Sibling taxa | ||
Synonyms | Scirpus atropurpureus | |
Name authority | (Retzius) J. Presl & C. Presl: in C. B. Presl, Reliq. Haenk. 1: 196. (1828) | Svenson: Rhodora 31: 203, fig. 27. (1929) |
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