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

Engelman spikerush, Engelmann's spike-rush, Engelmann's spikesedge, englemann's spike-rush

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

Culms

2–40 cm × 0.5–1.5(–2) mm.

2–35 cm × 0.3–1 mm.

Leaves

apex of distal leaf sheath obtuse to acute, tooth to 0.3 mm.

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

Spikelets

lanceoloid to subcylindric or ovoid, 5–10(–20) × 2–3(–4) mm, apex acute (to rounded);

proximal scale empty, encircling ca. 2/3 of culm;

floral scales 25–100(–200), 8–12 per mm of rachilla, orangebrown to stramineous, 2(–2.5) × 1–1.3 mm, midribs mostly keeled, ovate, apex narrowly rounded to subacute.

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.

Flowers

perianth bristles present or often absent, 5–8, brown, stout, rudimentary to slightly exceeding tubercle;

stamens (2–)3;

anthers brown to yellow, 0.3–0.7(–1) mm;

styles 2–3-fid.

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.

Achenes

0.9–1.1(–1.5) × 0.7–1.1 mm.

0.75–1 × 0.6–0.85 mm.

Tubercles

depressed, subdeltoid, 0.1–0.3(–0.4) × 0.6–0.9(–1) mm, 1/10–2/5 as high as wide, 1/4 or less as high as achene, 9/10 as wide as achene, very rarely 2/5 as high as achene (in E. engelmannii var. robusta).

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.

2n

= 10.

= 10.

Eleocharis engelmannii

Eleocharis ovata

Phenology Fruiting spring–fall. Fruiting summer–fall.
Habitat Fresh shores, marshes, disturbed places Fresh, often drying shores, lake and stream beds, bogs, tidal estuaries, disturbed places
Elevation 30–2400 m (100–7900 ft) 10–700 m (East), 1500–2000 m (Arizona) (0–2300 ft (East), 4900–6600 ft (Arizona))
Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; IA; ID; IL; IN; KS; KY; MA; MD; MI; MN; MO; MS; MT; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; TN; TX; VA; WA; WI; WV; AB; BC; MB; ON
[WildflowerSearch map]
[BONAP county map]
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]
Discussion

Robust plants known only from Missouri and described as Eleocharis engelmannii var. robusta have well-developed caudices, culms to 2 mm wide (pressed), spikelets to 2 cm, floral scales to 2.5 mm and slightly cartilaginous, styles mostly trifid, achenes to 1.5 × 1 mm, and tubercles 0.3–0.5 × 0.7–1 mm and to 2/5 as high as achene. Some specimens are intermediate between E. engelmannii and E. obtusa, or rarely with E. lanceolata. I have not seen specimens to verify literature reports of E. engelmannii from Manitoba, Connecticut, Delaware, Idaho, New Hampshire, North Carolina, Oregon, Rhode Island, South Carolina, South Dakota, or Vermont.

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

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.)

Source FNA vol. 23, p. 104. FNA vol. 23, p. 103.
Parent taxa Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae
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. 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
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
Synonyms E. engelmannii var. detonsa, E. engelmannii var. monticola, E. engelmannii var. robusta, E. monticola, E. monticola var. leviseta, E. ovata var. detonsa Scirpus ovatus, E. obtusa var. ovata, E. ovata var. heuseri
Name authority Steudel: Syn. Pl. Glumac. 2: 79. (1855) (Roth) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817)
Web links