Eleocharis engelmannii |
Eleocharis bernardina |
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Engelman spikerush, Engelmann's spike-rush, Engelmann's spikesedge, englemann's spike-rush |
fewflower spikerush |
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Habit | Plants perennial; rhizomes 0.5–1 mm thick, scales persistent, 5–8 mm, membranous, not fibrous; resting buds absent (non-resting buds on rhizome apex ellipsoid, 10 × 2–5 mm); caudices present, hard, 1–2 mm thick. | |
Culms | 2–40 cm × 0.5–1.5(–2) mm. |
markedly arched, not spirally twisted, not contracted near spikelet, when dry usually with several blunt to acute ridges and sulcate, subterete to slightly compressed, to 2 times as wide as thick, 5–15 cm × 0.5–1 mm, firm to hard; culm tufts not proximally bulbous. |
Leaves | apex of distal leaf sheath obtuse to acute, tooth to 0.3 mm. |
distal leaf sheaths brown to reddish proximally, stramineous to reddish distally, apex sometimes reddish, membranous to papery. |
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. |
3–6 × 2–4 mm; proximal scale empty, 2.5–4 mm, 1/2 or more as long as spikelet; floral scales 4–9 per spikelet, 3.5–5 × 2 mm. |
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 4–7, very unequal, some shorter than 1/2 of achene, stout and smooth, others equaling or exceeding tubercle, very slender and densely spinulose; anthers 1–1.5 mm. |
Achenes | 0.9–1.1(–1.5) × 0.7–1.1 mm. |
medium brown, equilaterally trigonous to compressed trigonous or some biconvex, 1.5–2.1 × 0.9–1.2 mm, beak 0.2–0.3 × 0.3–0.4 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). |
0.25–0.5 × 0.15–0.2 mm. |
2n | = 10. |
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Eleocharis engelmannii |
Eleocharis bernardina |
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Phenology | Fruiting spring–fall. | Fruiting summer. |
Habitat | Fresh shores, marshes, disturbed places | Wet meadows in conifer forests |
Elevation | 30–2400 m (100–7900 ft) | 2100–2700 m (6900–8900 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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CA |
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.) |
Of conservation concern. Although usually included in Eleocharis quinqueflora, E. bernardina is clearly more like E. suksdorfiana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 104. | FNA vol. 23. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae | Cyperaceae > Eleocharis > subg. Zinserlingia |
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 | Scirpus bernardinus, E. pauciflora var. bernardina, E. quinqueflora var. bernardina |
Name authority | Steudel: Syn. Pl. Glumac. 2: 79. (1855) | (Munz & I. M. Johnston) Munz: Man. S. Calif. Bot., 68, 597. (1935) |
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