Eleocharis geniculata |
Eleocharis nitida |
|
---|---|---|
bent spike-rush, Canada spikesedge, capitate spike-rush |
neat spike-rush, quill spike-rush, quill spikesedge, slender spikerush, éléocharide brillante |
|
Habit | Plants tufted, without creeping rhizomes. | Plants perennial, mat-forming; rhizomes evident, 0.3–0.5 mm thick, hard, cortex persistent, longer internodes 2 mm, scales persistent or fugaceous, 2–3 mm, membranous to papery, slightly fibrous. |
Culms | to 45 cm × 0.2–1 mm. |
terete, 2–15 cm × 0.15–0.3 mm, firm to soft. |
Leaves | distal leaf sheaths persistent, firm, distally tightly sheathing, apex acute. |
distal leaf sheaths persistent, not splitting, proximally stramineous to reddish, distally green or stramineous to reddish, membranous, apex often red, obtuse to acute, tooth absent. |
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. |
ovoid, 1–4 × 1–2 mm, obtuse to acute; proximal scale amplexicaulous, apex entire; subproximal scale with flower; floral scales spreading in fruit, 5–30, 8 per mm of rachilla, medium to very dark brown, midrib region often pale or greenish, broadly ovate, 1–1.3 × 1 mm, apex rounded, entire, not carinate. |
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 absent; stamens 3; anthers yellow, 0.3 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. |
persistent after scales fall, to dark yellow-orange or brown, broadly obpyriform, trigonous, angles evident, 0.6–0.65 × 0.5–0.55 mm, rugulose at 20–30X, 20 blunt horizontal ridges in each vertical series. |
Tubercles | stramineous to whitish, umbonate to subconic, 0.2–0.4 × 0.2–0.5 mm, apex rounded to acute. |
brown, greatly depressed, rudimentary, 0.05–15 × 0.15–0.3 mm. |
2n | = 10. |
|
Eleocharis geniculata |
Eleocharis nitida |
|
Phenology | Fruiting spring–winter (Mar–Dec). | Fruiting late spring (Jun)–summer. |
Habitat | Brackish creeks, canal banks, dune depressions, hammocks, irrigation ditches, lakeshores, lagoons, mangrove thickets, maritime mud flats, ditches, salt marshes | Fresh bog pools, streams, disturbed places |
Elevation | 0–1500 m (0–4900 ft) | 30–400 m (100–1300 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
|
AK; MI; MN; NH; WI; NL; NS; ON; QC; SK |
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.) |
Eleocharis nitida is much like E. elliptica but all structures are smaller; intermediates are unknown. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 101. | FNA vol. 23, p. 86. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis |
Sibling taxa | ||
Synonyms | Scirpus geniculatus, E. capitata, E. caribaea, E. dispar | |
Name authority | (Linnaeus) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 150. (1817) | Fernald: Rhodora 8: 129. (1906) |
Web links |