Eleocharis geniculata |
Eleocharis nana |
|
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bent spike-rush, Canada spikesedge, capitate spike-rush |
hair-like spikerush |
|
Habit | Plants tufted, without creeping rhizomes. | 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 45 cm × 0.2–1 mm. |
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 persistent, firm, distally tightly sheathing, apex acute. |
distal leaf sheaths persistent or fugaceous, pale brown or red-brown sometimes spotted or streaked red-brown, translucent, membranous, apex acute. |
Spikelets | orbicular to ovoid, 1–9 × 1–4 mm, apex rounded to acute; proximal scale without flower, not amplexicaulous; floral scales to 125, 11–14 per mm of rachilla, tightly appressed, dark red-brown to stramineous, ovate to elliptic, 0.8–3 × 0.6–2(–2.3) mm, membranous to cartilaginous, apex rounded to acute. |
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 (0–)4–8, typically 7, red-brown, rarely whitish, vestigial to much exceeding tubercle, typically equaling achene, spinules few to dense; styles 2-fid. |
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 | brown ripening to black, biconvex, orbicular to obpyriform, 0.5–1.1 × 0.3–0.7 mm, apex rarely constricted proximal to tubercle, very finely reticulate at 40X. |
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 | stramineous to whitish, umbonate to subconic, 0.2–0.4 × 0.2–0.5 mm, apex rounded to acute. |
white or red-brown, pyramidal, trigonous, 0.2–0.4 × 0.3–0.4 mm. |
2n | = 10. |
|
Eleocharis geniculata |
Eleocharis nana |
|
Phenology | Fruiting spring–winter (Mar–Dec). | Fruiting summer–winter. |
Habitat | Brackish creeks, canal banks, dune depressions, hammocks, irrigation ditches, lakeshores, lagoons, mangrove thickets, maritime mud flats, ditches, salt marshes | Freshwater, moist terrestrial sites such as sandy and peaty ponds, cypress swamps |
Elevation | 0–1500 m (0–4900 ft) | 10–50 m (0–200 ft) |
Distribution |
AL; AZ; CA; FL; GA; IL; IN; LA; MI; MS; NE; NM; NV; OH; OK; PA; TX; ON; Mexico; Central America; South America; West Indies; Bermuda; Asia; Africa; Pacific Islands
|
FL; South America |
Discussion | The name Eleocharis caribaea (Rottbøll) S. F. Blake is considered by most contemporary authorities to be misapplied (K. L. Wilson 1990). Eleocharis geniculata has been reported from South Carolina; I have not seen a voucher. (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. 101. | FNA vol. 23, p. 95. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae |
Sibling taxa | ||
Synonyms | Scirpus geniculatus, E. capitata, E. caribaea, E. dispar | Chaetocyperus punctatus, E. camptotricha, E. punctata, Scirpus camptotrichus |
Name authority | (Linnaeus) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 150. (1817) | Kunth: Enum. Pl. 2: 140. (1837) |
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