The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

beak spike-rush, beak spikesedge, walking sedge, walking spikerush

white spikerush

Habit Plants densely tufted, mat-forming by means of rooting culm tips. Plants perennial; rhizomes soft, longer internodes 2–4 cm, cortex loose, scales fugaceous, 6 mm, thinly membranous and translucent.
Culms

1.5–3 times as wide as thick, 20–100 cm × 0.35–2 mm, firm to hard, wiry, with to 8 subacute ribs, rarely nearly smooth;

some culms arching or decumbent and rooting at tips.

not rooting at tips, terete, 10–40 cm, soft to firm, smooth.

Leaves

distal leaf sheaths not splitting abaxially, proximally dark red to brown, apex usually reddish.

distal leaf sheaths proximally brownish or sometimes reddish, distally stramineous to green.

Spikelets

ovoid, 5–17 × 2.5–5 mm, apex acute;

spikelets on stolons rudimentary, non-flowering, proliferous when rooting;

proximal scale empty, amplexicaulous, ovate, 2–4 mm;

subproximal scale with flower;

floral scales 20–40, 2–3 per mm of rachilla, stramineous to medium brown, midrib region paler, ovate, 3.5–6 × 2–3 mm, membranous to cartilaginous, apex entire, rounded to subacute.

ovoid to oblong-subcylindric, 4–12 × 2–3.5 mm, apex acute to rounded;

proximal scale empty, clasping 1/2 of culm, like floral scales;

subproximal 1 or 2 scales often empty;

floral scales 20–100, 10 per mm of rachilla, entirely stramineous or sometimes red-brown, ovate, (1.5–)2–2.5 × 1.5 mm, apex broadly rounded, entire.

Flowers

perianth bristles brown, equaling achene or tubercle, densely spinulose;

anthers brown, 2–2.4 mm.

perianth bristles (5–)6(–8), brown, stout, the longer equaling achene or tubercle, retrorsely spinulose;

stamens 3;

anthers brown, 1 mm.

Achenes

often very variable within one plant, ovoid to obovoid or obpyriform, 1.5–2.5 × 1–1.2 mm, beak to 1 × 0.6 mm.

falling with scales, obovoid, angles keeled, 0.8–1 × 0.7–0.8 mm, apex with short neck.

Tubercles

when present pale to dark brown, pyramidal, to 0.5 × 0.3 mm.

whitish to brown, mammillate to pyramidal, 0.2–0.3 × 0.3–0.35 mm, 1/3 or less as wide as achene.

Eleocharis rostellata

Eleocharis albida

Phenology Fruiting late spring in south, summer–fall in north. Fruiting summer.
Habitat Very wet calcareous or brackish fens, springs, shores Coastal saltmarsh edges, sloughs, beaches, dune depressions, ditches
Elevation 50–2400 m (200–7900 ft) 0 m (0 ft)
Distribution
from FNA
AZ; CA; CT; DE; FL; ID; IL; IN; KS; LA; MA; MD; ME; MI; MN; MT; NC; NE; NJ; NM; NV; NY; OH; OK; PA; RI; SC; SD; TX; UT; VA; WA; WI; WY; BC; NS; ON; Mexico; West Indies (Cuba, Haiti, Puerto Rico)
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; LA; MD; MS; NC; NM; SC; TX; Mexico; Bermuda
[WildflowerSearch map]
[BONAP county map]
Discussion

Eleocharis rostellata is highly competitive, often forming large monospecific colonies. The South American E. platypus C. B. Clarke is often treated as a synonym of E. rostellata. Eleocharis rostellata superfically closely resembles E. suksdorfiana in its culms, spikelets, and achenes, but differs in the absence of creeping rhizomes, presence of stoloniferous culms, absence of a flower in the proximal scale, and achene surface details. The collection of E. rostellata I have seen from Miami-Dade County, Florida, is from 1877. I have not seen vouchers for Archuleta County, Colorado, by H. D. Harrington (1954), or for the localities in Montana and South Carolina, which are based on the map in H. K. Svenson (1934).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

In most spikelets, the bright brown stigmas contrast strikingly with the stramineous floral scales. We have not seen vouchers for H. K. Svenson’s (1937) reports of Eleocharis albida from Virginia. The collections we have seen from Maryland are from the 1800s.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 90. FNA vol. 23, p. 99.
Parent taxa Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Rostellatae Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Albidae
Sibling taxa
E. acicularis, E. aestuum, E. albida, E. ambigens, E. atropurpurea, E. baldwinii, E. bella, E. bernardina, E. bicolor, E. bifida, E. bolanderi, E. brachycarpa, E. brittonii, E. cancellata, E. cellulosa, E. coloradoensis, E. compressa, E. cylindrica, E. decumbens, E. diandra, E. elliptica, E. elongata, E. engelmannii, E. equisetoides, E. erythropoda, E. fallax, E. flavescens, E. geniculata, E. intermedia, E. interstincta, E. kamtschatica, E. lanceolata, E. macrostachya, E. mamillata, E. melanocarpa, E. microcarpa, E. minima, E. montana, E. montevidensis, E. nana, E. nigrescens, E. nitida, E. obtusa, E. obtusetrigona, E. occulta, E. ovata, E. pachycarpa, E. palustris, E. parishii, E. parvula, E. quadrangulata, E. quinqueflora, E. radicans, E. ravenelii, E. retroflexa, E. reverchonii, E. robbinsii, E. suksdorfiana, E. tenuis, E. torticulmis, E. tortilis, E. tricostata, E. tuberculosa, E. uniglumis, E. vivipara, E. wolfii
E. acicularis, E. aestuum, E. ambigens, E. atropurpurea, E. baldwinii, E. bella, E. bernardina, E. bicolor, E. bifida, E. bolanderi, E. brachycarpa, E. brittonii, E. cancellata, E. cellulosa, E. coloradoensis, E. compressa, E. cylindrica, E. decumbens, E. diandra, E. elliptica, E. elongata, E. engelmannii, E. equisetoides, E. erythropoda, E. fallax, E. flavescens, E. geniculata, E. intermedia, E. interstincta, E. kamtschatica, E. lanceolata, E. macrostachya, E. mamillata, E. melanocarpa, E. microcarpa, E. minima, E. montana, E. montevidensis, E. nana, E. nigrescens, E. nitida, E. obtusa, E. obtusetrigona, E. occulta, E. ovata, E. pachycarpa, E. palustris, E. parishii, E. parvula, E. quadrangulata, E. quinqueflora, E. radicans, E. ravenelii, E. retroflexa, E. reverchonii, E. robbinsii, E. rostellata, E. suksdorfiana, E. tenuis, E. torticulmis, E. tortilis, E. tricostata, E. tuberculosa, E. uniglumis, E. vivipara, E. wolfii
Synonyms Scirpus rostellatus
Name authority (Torrey) Torrey: Fl. New York 2: 347. (1843) Torrey: Ann. Lyceum Nat. Hist. New York. 3: 304. (1836)
Web links