Eleocharis melanocarpa |
Eleocharis nana |
|
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black-fruit spike-rush, black-fruit spikesedge |
hair-like spikerush |
|
Habit | Plants probably perennial, tufted; rhizomes present, ± horizontal, 0.3–0.5 mm thick, soft, longer internodes 5 mm, scales disintegrating, translucent or not. | |
Culms | 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. |
erect to ascending, ± quadrangular to pentagonal or broadly elliptic, sometimes sulcate, (1.9–)4.2–8.6 cm (extraterritorial plants to 12 cm) × 0.2–0.4 mm, soft. |
Leaves | distal leaf sheaths brown to reddish. |
distal leaf sheaths persistent or fugaceous, pale brown or red-brown sometimes spotted or streaked red-brown, translucent, membranous, apex acute. |
Spikelets | 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. |
basal spikelets absent; never proliferous, ovoid, ellipsoid or obovoid, laterally compressed when young, but terete at maturity, 1.9–4 × 1–3 mm, apex acute, proximal scale empty, deciduous, amplexicaulous or nearly so, similar to floral scales, 0.6–2.5 × 0.8–1.2 mm, midrib sometimes slightly prolonged beyond lamina; subproximal scale with a flower; floral scales distichous or spirodistichous, (2–) 4–10, 3–5 per mm of rachilla, pale brown, spotted or streaked red-brown, ovate or elliptic, 1.7–2.2 × 0.4–0.7 mm, membranous, midrib green, spotted red-brown, prominent, apex rounded. |
Flowers | perianth bristles present, sometimes rudimentary, brown, length variable, obscurely retrorsely spinulose; anthers brown, 1.7–2.2 mm. |
perianth bristles 6, red-brown, equaling to much exceeding tubercle; spinules sparse, retrorse, sharply acute; stamens 3; anthers 0.5–0.7 × 0.1 mm; styles 3-fid. |
Achenes | subdeltoid in outline, sometimes broadly obpyriform, equilaterally trigonous, angles prominent, 0.9–1.2 × 0.7–1.1 mm, apex truncate. |
whitish or pale brown, circular in outline, ellipsoid, or obovoid, trigonous, angles prominent, 0.6–0.8 × 0.5–0.6(–0.7) mm, apex constricted proximal to tubercle, smooth. |
Tubercles | sessile, depressed-pyramidal, often apiculate, as wide as achene, 0.3–0.5 × 0.7–1.1 mm. |
white or red-brown, pyramidal, trigonous, 0.2–0.4 × 0.3–0.4 mm. |
Eleocharis melanocarpa |
Eleocharis nana |
|
Phenology | Fruiting summer. | Fruiting summer–winter. |
Habitat | Fresh, oligotrophic, acid, sandy or peaty, often drying shores, ponds, ditches | Freshwater, moist terrestrial sites such as sandy and peaty ponds, cypress swamps |
Elevation | 10–300 m (0–1000 ft) | 10–50 m (0–200 ft) |
Distribution |
AL; FL; GA; IN; MA; MI; NC; NY; RI; SC; TX; VA
|
FL; South America |
Discussion | Eleocharis melanocarpa is reported from Rhode Island; I have not seen a voucher specimen. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
H. K. Svenson (1957) described Eleocharis nana as “annual (?),” but the presence of rhizomes suggests that this species may be perennial. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 89. | FNA vol. 23, p. 95. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Melanocarpae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae |
Sibling taxa | ||
Synonyms | Chaetocyperus punctatus, E. camptotricha, E. punctata, Scirpus camptotrichus | |
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 311. (1836) | Kunth: Enum. Pl. 2: 140. (1837) |
Web links |