Eleocharis quadrangulata

(Michaux) Roemer & Schultes in J. J. Roemer et al.

in J. J. Roemer et al., Syst. Veg. 2: 155. 1817.

Common names: Square-stemmed spike-rush
Illustrated
Basionym: Scirpus quadrangulatus Michaux Fl. Bor.-Amer. 1: 30. 1803
Synonyms: Eleocharis quadrangulata var. crassior Fernald Scirpus albomarginatus Muhlenberg Scirpus marginatus
Treatment appears in FNA Volume 23. Treatment on page 120. Mentioned on page 117, 118, 119.

Plants perennial; rhizomes 1.5–4 mm thick, soft to hard, longer internodes 3–8 cm, scales 5–10 mm, tubers absent. Culms acutely quadrangular, (30–) 45–105 cm × (1–) 2–5.4 mm, soft to firm, internally spongy, transverse septa incomplete; plants never forming filiform, flaccid culms. Leaves: distal leaf-sheaths persistent, membranous, apex narrowly acute to acuminate, sometimes prolonged into a bladelike portion to 8 cm. Spikelets not proliferous, (15–) 20–76 × 3–5 (–6) mm; rachilla joints bearing obscure winglike remnants of floral scales; proximal scale empty, amplexicaulous, (1–) 2.2–5.4 mm; floral scales (28–) 45–135, 2–3 per mm of rachilla, stramineous to pale-brown, usually with pale to dark-brown submarginal band, midrib region sometimes greenish, broadly obovate to ovate, (4–) 4.5–6.2 × 2.8–5 mm, subcartilaginous, apex rounded to obtuse. Flowers: perianth bristles 6–7, whitish to brown, slender, often markedly unequal, shorter than achene or some equalling tubercle, sparsely retrorsely spinulose to smooth; anthers stramineous to redbrown, 2.3–2.9 mm; styles 3-fid, sometimes 2-fid. Achenes yellow or pale green to brown or purplish, biconvex, obovoid to obpyriform, 1.8–3 × 1.3–2 mm, almost smooth to markedly sculptured at 10–15X, each face with 19–38 rows of almost linear, transversely elongated cells, which sometimes isodiametric at achene base, apex often constricted to neck 0.3–0.4 mm wide. Tubercles dark-brown or whitish, deltoid to high-pyramidal or lanceoloid, 0.7–1.5 × 0.4–1 mm, often spongy.


Phenology: Fruiting early summer–winter.
Habitat: Shallow water of fresh lake and pond shores, marshes
Elevation: 10–600 m

Distribution

V23 183-distribution-map.jpg

Ont., Ark., Calif., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Mass., Mich., Miss., Mo., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., S.C., Tex., Va., W.Va., Wis., s to c Mexico

Discussion

We have not seen voucher specimens for the reports of Eleocharis quadrangulata from Kansas. Plants with greenish achenes, longer bristles, and longer anthers than the average are known from Tennessee.

The tubercles of Eleocharis quadrangulata are often spongy as in E. obtusetrigona.

Selected References

None.

Lower Taxa

None.

"prolonged" is not a number.

... more about "Eleocharis quadrangulata"
pale green +  and brown or purplish +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
smooth +  and markedly sculptured +
obovoid;obpyriform +
constricted +
1.3mm;2mm +
stramineous;redbrown +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
constricted +
M. Socorro González-Elizondo +
(Michaux) Roemer & Schultes in J. J. Roemer et al. +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
shortened +
persistent +
enlarged +
Scirpus quadrangulatus +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
enlarged +
Square-stemmed spike-rush +
30 cm300 mm <br />0.3 m <br /> (45 cm450 mm <br />0.45 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
45 cm450 mm <br />0.45 m <br /> (105 cm1,050 mm <br />1.05 m <br />) +
filiform +  and quadrangular +
flaccid;spongy;soft;firm +
2mm;5.4mm +
Ont. +, Ark. +, Calif. +, Conn. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Ky. +, La. +, Mass. +, Mich. +, Miss. +, Mo. +, N.J. +, N.Y. +, N.C. +, Ohio +, Okla. +, Oreg. +, Pa. +, S.C. +, Tex. +, Va. +, W.Va. +, Wis. +  and s to c Mexico +
10–600 m +
stramineous +  and pale-brown +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
papery +  and cartilaginous +
subtending +
biconvex +  and trigonous +
Shallow water of fresh lake and pond shores, marshes +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.62 cm6.2 mm <br />0.0062 m <br />) +
broadly obovate +  and ovate +
subcartilaginous +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
distinct +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (?) +  and 0.04 cm0.4 mm <br />4.0e-4 m <br /> (?) +
sparsely retrorsely spinulose +  and smooth +
unequal +  and slender +
with (1-)3-6(-30) bristles and/or scales +
Fruiting early summer–winter. +
2-3(-4)-carpellate +
0 cm0 mm <br />0 m <br /> (8 cm80 mm <br />0.08 m <br />) +
3 (?) +  and 1 (?) +
amplexicaulous +  and empty +
0.1 cm1 mm <br />0.001 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
stramineous;medium brown or red brown or blackish brown +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.54 cm5.4 mm <br />0.0054 m <br />) +
in J. J. Roemer et al., Syst. Veg. +
ascending +  and horizontal +
caudex-like +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
adventitious +
basal +  and proximal +
2-keeled +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
cylindric +
W1 +  and Illustrated +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
2 cm20 mm <br />0.02 m <br /> (7.6 cm76 mm <br />0.076 m <br />) +
not proliferous +
terete;cylindric;narrowly ellipsoid +
0.9 cm9 mm <br />0.009 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
1 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
2-fid +  and 3-fid +
pale +  and dark-brown +
Eleocharis quadrangulata var. crassior +, Scirpus albomarginatus +  and Scirpus marginatus +
Eleocharis quadrangulata +
Eleocharis subg. Limnochloa +
species +
whitish;dark-brown +
0.7mm;1.5mm +
deltoid +  and high-pyramidal or lanceoloid +
0.4mm +  and 1mm +
stoloniferous +  and rhizomatous +