Eleocharis flavescens

(Poiret) Urban

Symb. Antill. 4: 116. 1903.

Common names: Pale spike-rush wrinkle-sheathed spike-rush
Illustrated
Basionym: Scirpus flavescens Poiret in J. Lamarck et al., Encycl. 6: 756. 1804
Treatment appears in FNA Volume 23. Treatment on page 100. Mentioned on page 63, 101.

Plants with creeping rhizomes 0.5–1 mm thick. Culms 3–42 cm × 0.3–0.6 mm. Leaves: distal leaf-sheaths often disintegrating, thinly membranous-translucent, inflated distally, often wrinkled, apex blunt. Spikelets ellipsoid, 1.5–9 × 1–3.5 mm, apex acute to acuminate; proximal scale without flower, not amplexicaulous; floral scales to 65, 5–7 per mm of rachilla, loosely appressed to appressed, elliptic, 1–3 × 0.4–1.6 mm, membranous, apex acute. Flowers: perianth bristles (0–) 5–8, typically 7, white to stramineous, spinules dense to few; styles 2-fid, rarely 3-fid. Achenes stramineous to green or dark-brown, biconvex, rarely trigonous, obovoid to obpryiform, 0.4–1.1 × 0.3–0.8 mm, very finely reticulate at 40X. Tubercles whitish to stramineous or green, 0.2–0.7 × 0.2–0.4 mm, apex acute to acuminate.

Distribution

V23 148-distribution-map.jpg

N.B., N.S., Ont., Que., Ala., Ariz., Ark., Calif., Conn., Del., Fla., Ga., Idaho, Ill., Ind., La., Maine, Mass., Md., Mich., Minn., Miss., Mont., N.C., N.H., N.J., N.Y., Ohio, Pa., R.I., S.C., Tex., Utah, Va., Vt., Wis., Wyo., temperate North America, West Indies, South America

Discussion

Varieties 2 (2 in the flora).

The varieties of Eleocharis flavescens are difficult to delimit, especially in the south, and identifications of some specimens to variety are problematic.

Selected References

None.

Key

1 Achenes red-brown to dark brown when ripe, 0.4–0.8(–1.1) × 0.3–0.6 mm, apex rarely highly constricted proximal to tubercle; flowers with perianth bristles typically shorter than to as long as achene. Eleocharis flavescens var. flavescens
1 Achenes green to golden-brown, 0.5–1.1 × 0.4–0.8 mm, often highly constricted proximal to tubercle; flowers with perianth bristles typically longer than achene. Eleocharis flavescens var. olivacea

"shortened" is not a number.

... more about "Eleocharis flavescens"
stramineous +  and green or dark-brown +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
obovoid;trigonous;biconvex +
0.3mm;0.8mm +
acute;acuminate +
constricted +
Francis J. Menapace +
(Poiret) Urban +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
persistent +
enlarged +
Scirpus flavescens +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
Pale spike-rush +  and wrinkle-sheathed spike-rush +
3 cm30 mm <br />0.03 m <br /> (42 cm420 mm <br />0.42 m <br />) +
0.3mm;0.6mm +
N.B. +, N.S. +, Ont. +, Que. +, Ala. +, Ariz. +, Ark. +, Calif. +, Conn. +, Del. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, La. +, Maine +, Mass. +, Md. +, Mich. +, Minn. +, Miss. +, Mont. +, N.C. +, N.H. +, N.J. +, N.Y. +, Ohio +, Pa. +, R.I. +, S.C. +, Tex. +, Utah +, Va. +, Vt. +, Wis. +, Wyo. +, temperate North America +, West Indies +  and South America +
loosely appressed +  and appressed +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
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 +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
not amplexicaulous +
stramineous;medium brown or red brown or blackish brown +
Symb. Antill. +
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 +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
ellipsoid +
1mm;3.5mm +
1 +  and 3 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
3-fid +  and 2-fid +
Eleocharis +
Eleocharis flavescens +
Eleocharis (sect. Eleogenus) ser. Maculosae +
species +
whitish;stramineous or green +
0.2mm;0.7mm +
compressed +
0.2mm +  and 0.4mm +
not +  and rhizomatous +
perennial +  and annual +