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ovate spike-rush, ovoid spike-rush, ovoid spikesedge, éléocharide ovale

Wolf's spike-rush

Habit Plants perennial, often forming large mats; rhizomes 0.25–0.6 mm thick, internodes 1–4 cm, scales 2 mm.
Culms

2–35 cm × 0.3–1 mm.

sometimes decumbent, in same plant sides variably smooth or with 1 to few acute ridges (often nearly smooth or with 1 ridge on 1 side and several ridges on the other), greatly compressed, usually inrolled when dry, rectangular in cross section, 10–40 cm × 0.3–1.5 mm, 0.2–0.5 mm thick, firm, margins often sharply acute, margins and often 1 or more ridges minutely serrulate at 20–30X.

Leaves

apex of distal leaf sheath obtuse to acute, tooth to 0.2 mm.

distal leaf sheaths persistent, red proximally, colorless or stramineous or whitish distally, slightly inflated, thickly membranous, apex acute.

Spikelets

ovoid, 2–8 × 2–4 mm, apex acute (to blunt);

floral scales 25–100+, ca. 10 per mm of rachilla, orange-brown, rarely stramineous, ovate, 1.5–2 × 1 mm, midribs often keeled in distal part of spikelet, apex rounded to subacute.

ovoid or lanceoloid, 3–9 × 1.5–2.5 mm, apex acute;

floral scales 15–30, 6 per mm of rachilla, orange-brown or often stramineous or colorless, midrib region stramineous or greenish, ovate-lanceolate, (2.2–)2.7–3.2 × 1.5 mm, midrib prominent, apex acute.

Flowers

perianth bristles present, rarely absent, (5–)6–7, brown, fairly slender, exceeding tubercle;

stamens 2(–3);

anthers brown, 0.3 mm;

styles 2-fid or some 3-fid.

perianth bristles absent;

anthers 1.1–1.75 mm.

Achenes

0.75–1 × 0.6–0.85 mm.

compressed-trigonous, with angles plus longitudinal ridges ca. 9–13, prominent, obovoid, mostly 2 times longer than wide, 0.7–0.9(–1.1) × (0.4–)0.5 mm, trabeculae 30–60, rather obscure and crowded.

Tubercles

deltoid, 0.3–0.5 × 0.3–0.5 mm, 3/5 of to as high as wide, 1/3–2/3 as high and 1/2–3/4 as wide as achene.

brownish, pyramidal, usually depressed, 0.1–0.15 × 0.2–0.25 mm.

2n

= 10.

Eleocharis ovata

Eleocharis wolfii

Phenology Fruiting summer–fall. Fruiting late spring–early summer (May–Jun).
Habitat Fresh, often drying shores, lake and stream beds, bogs, tidal estuaries, disturbed places Ephemeral pools in open grasslands, oak woodlands on river terraces, limestone barrens
Elevation 10–700 m (East), 1500–2000 m (Arizona) (0–2300 ft (East), 4900–6600 ft (Arizona)) 10–500 m (0–1600 ft)
Distribution
from FNA
AZ; CT; IA; IL; IN; KY; MA; ME; MI; MN; MO; NH; NJ; NY; OH; OK; OR; PA; VA; VT; WA; WI; WV; AB; BC; NB; NL; NS; ON; PE; QC; Eurasia
[WildflowerSearch map]
from FNA
AL; AR; CO; IA; IL; IN; KS; LA; MN; MO; MS; ND; NY; OH; OK; TN; TX; WI
[WildflowerSearch map]
[BONAP county map]
Discussion

Although Eleocharis ovata has often been confused with E. obtusa, B. M. H. Larson and P. M. Catling (1996) showed that these species may be distinguished by non-overlapping widths of the tubercles, at least in Canada. The records of E. ovata in New Brunswick, Newfoundland, Nova Scotia, and Prince Edward Island are based on B. M. H. Larson and P. M. Catling (1996) and the records in Illinois, Indiana, Missouri, Montana, New Jersey, Oregon, and Washington are based on D. M. Hines (1975). Eleocharis ovata probably also occurs in Manitoba and Saskatchewan.

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

Eleocharis wolfii is presumably extirpated from Colorado, Kansas, New York (Long Island), and Ohio. It was recently rediscovered in Wisconsin. Some literature reports (e.g. from the Great Plains) are based on misidentified specimens. I have not seen specimens to verify literature reports from Alberta, Saskatchewan, Colorado, Missouri, and Nebraska.

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

Source FNA vol. 23, p. 103. FNA vol. 23, p. 110.
Parent taxa Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae Cyperaceae > Eleocharis > subg. Scirpidium
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. 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
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. rostellata, E. suksdorfiana, E. tenuis, E. torticulmis, E. tortilis, E. tricostata, E. tuberculosa, E. uniglumis, E. vivipara
Synonyms Scirpus ovatus, E. obtusa var. ovata, E. ovata var. heuseri Scirpus wolfii
Name authority (Roth) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817) (A. Gray) A. Gray ex Britton: in H. N. Patterson, Cat. Pl. Illinois, 46. (1876)
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