Eleocharis geniculata |
Eleocharis reverchonii |
|
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bent spike-rush, Canada spikesedge, capitate spike-rush |
Reverchon's spikerush |
|
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 | to 45 cm × 0.2–1 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 persistent, firm, distally tightly sheathing, apex acute. |
distal leaf sheaths persistent, red proximally, colorless distally, closely sheathing, apex blunt. |
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, 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–)4–8, typically 7, red-brown, rarely whitish, vestigial to much exceeding tubercle, typically equaling achene, spinules few to dense; styles 2-fid. |
perianth bristles absent; anthers 0.5–1 × 0.2 mm. |
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. |
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, 0.2–0.4 × 0.2–0.5 mm, apex rounded to acute. |
brownish to whitish, pyramidal to depressed, 0.1–0.15 × 0.1–0.2 mm. |
2n | = 10. |
|
Eleocharis geniculata |
Eleocharis reverchonii |
|
Phenology | Fruiting spring–winter (Mar–Dec). | Fruiting late winter–spring (Feb–Apr). |
Habitat | Brackish creeks, canal banks, dune depressions, hammocks, irrigation ditches, lakeshores, lagoons, mangrove thickets, maritime mud flats, ditches, salt marshes | Wet soil of ponds, marshes, grasslands, ditches |
Elevation | 0–1500 m (0–4900 ft) | 10–200 m (0–700 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
|
TX |
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.) |
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. 101. | FNA vol. 23, p. 110. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Maculosae | Cyperaceae > Eleocharis > subg. Scirpidium |
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) | Svenson: Rhodora 31: 203, fig. 27. (1929) |
Web links |