Eleocharis engelmannii

Steudel

Syn. Pl. Glumac. 2: 79. 1855.

Common names: Engelmann’s spike-rush
IllustratedEndemic
Synonyms: Eleocharis engelmannii var. detonsa A. Gray Eleocharis engelmannii var. monticola (Fernald) Svenson Eleocharis engelmannii var. robusta Fernald Eleocharis monticola Eleocharis monticola var. leviseta Fernald Eleocharis ovata var. detonsa (A. Gray) Mohlenbrock
Treatment appears in FNA Volume 23. Treatment on page 104. Mentioned on page 64, 65, 105.

Culms 2–40 cm × 0.5–1.5 (–2) mm. Leaves: apex of distal leaf-sheath obtuse to acute, tooth to 0.3 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. 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. Achenes 0.9–1.1 (–1.5) × 0.7–1.1 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). 2n = 10.


Phenology: Fruiting spring–fall.
Habitat: Fresh shores, marshes, disturbed places
Elevation: 30–2400 m

Distribution

V23 158-distribution-map.jpg

Alta., B.C., Man., Ont., Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Kans., Ky., Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y., N.Dak., Ohio, Okla., Oreg., Pa., R.I., Tenn., Tex., Va., Wash., W.Va., Wis.

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.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis engelmannii"
0.11 cm1.1 mm <br />0.0011 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
dark-brown +  and stramineous +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
biconvex +
0.7mm;1.1mm +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
brown;yellow +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
not constricted +
S. Galen Smith* +, Jeremy J. Bruhl* +, M. Socorro González-Elizondo* +  and Francis J. Menapace* +
Steudel +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
shortened +
persistent +
enlarged +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
Engelmann’s spike-rush +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2 cm20 mm <br />0.02 m <br /> (40 cm400 mm <br />0.4 m <br />) +
0.5mm;1.5mm +
green +  and stramineous +
Alta. +, B.C. +, Man. +, Ont. +, Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Mont. +, Nebr. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, Tenn. +, Tex. +, Va. +, Wash. +, W.Va. +  and Wis. +
30–2400 m +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
orangebrown +  and stramineous +
2 cm20 mm <br />0.02 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
Fresh shores, marshes, disturbed places +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
ovate +  and keeled +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
Fruiting spring–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
stramineous;medium brown or red brown or blackish brown +
Syn. Pl. Glumac. +
ascending +  and horizontal +
caudex-like +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
adventitious +
basal +  and proximal +
2-keeled +
cylindric +
Illustrated +  and Endemic +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
lanceoloid;subcylindric or ovoid +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
2-3-fid +
Eleocharis engelmannii var. detonsa +, Eleocharis engelmannii var. monticola +, Eleocharis engelmannii var. robusta +, Eleocharis monticola +, Eleocharis monticola var. leviseta +  and Eleocharis ovata var. detonsa +
Eleocharis engelmannii +
Eleocharis (sect. Eleogenus) ser. Ovatae +
species +
0 cm0 mm <br />0 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.1mm;0.3mm +
less +, 1/4 +, 1/10 +  and 2/5 +
subdeltoid +  and depressed +
0.6mm +  and 0.9mm +