Eleocharis engelmannii |
Eleocharis lanceolata |
|
---|---|---|
Engelman spikerush, Engelmann's spike-rush, Engelmann's spikesedge, englemann's spike-rush |
daggerleaf spikerush |
|
Culms | 2–40 cm × 0.5–1.5(–2) mm. |
20–35 cm × 0.3–1 mm. |
Leaves | apex of distal leaf sheath obtuse to acute, tooth to 0.3 mm. |
apex of distal leaf sheath subacute to narrowly acute, tooth to 0.3(–1.1) 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. |
narrowly lanceoloid, 3–12 × (1–)2–2.5(–4) mm, apex acute; floral scales 25–100, 10–12 per mm of rachilla, orangebrown to stramineous, ovate, 1.5–2 × 1 mm, midribs mostly keeled, apex acute or narrowly rounded in proximal part of spikelet. |
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 6–7, brown, stout, the longest equaling or exceeding tubercle; stamens 2–3; anthers brown, 0.3 mm; styles 2-fid. |
Achenes | 0.9–1.1(–1.5) × 0.7–1.1 mm. |
0.9–1.1 × 0.6–0.8 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, 0.25–0.5 × 0.5–0.7 mm, 1/2–2/3 as high as wide, 1/4–1/2 as high and 2/3–4/5 as wide as achene. |
2n | = 10. |
= 10. |
Eleocharis engelmannii |
Eleocharis lanceolata |
|
Phenology | Fruiting spring–fall. | Fruiting summer to fall. |
Habitat | Fresh shores, marshes, disturbed places | Fresh shores, stream beds, pine woods, disturbed places |
Elevation | 30–2400 m (100–7900 ft) | 0–400 m (0–1300 ft) |
Distribution |
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
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AR; CA; KS; LA; MO; OK; TN; TX |
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.) |
Some collections of Eleocharis lanceolata from Tennessee appear to be intermediate with E. obtusa. The California record is an introduced rice-field weed collected in 1949. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 104. | FNA vol. 23, p. 104. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae |
Sibling taxa | ||
Synonyms | E. engelmannii var. detonsa, E. engelmannii var. monticola, E. engelmannii var. robusta, E. monticola, E. monticola var. leviseta, E. ovata var. detonsa | |
Name authority | Steudel: Syn. Pl. Glumac. 2: 79. (1855) | Fernald: Proc. Amer. Acad. Arts 34: 493, figs. 27–29. (1899) |
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