Eleocharis bifida

S. G. Smith

Novon 11: 243, figs. 1F–J, 2. 2001.

Treatment appears in FNA Volume 23. Treatment on page 85. Mentioned on page 67, 83, 84, 86.

Plants perennial, densely cespitose; rhizomes concealed by persistent culm bases, short, 4–5 mm thick, hard, cortex persistent, internodes crowded, scales decaying to coarse fibers, 1 cm, papery. Culms greatly compressed, 4–10 times wider than thick, often with 1 or 2 sharp ridges on 1 side, (8–) 20–35 cm × 0.7–2.3 mm, hard, finely striate, spongy. Leaves: distal leaf-sheaths persistent, not splitting, proximally red or stramineous, distally green to stramineous, inflated, papery, apex dark-brown, broadly obtuse to subtruncate, callose, tooth absent. Spikelets ovoid, 4–9 × 2.5–4 mm, apex acute; proximal scale clasping 2/3–3/4 of culm, apex 2-fid; subproximal scale empty or with a flower; floral scales spreading in fruit, 30–60, 6–9 per mm of rachilla, medium or pale-brown, midrib region often paler, ovatelanceolate, 2.5–3.5 × 1.5 mm, apex 2-fid, carinate in distal part of spikelet. Flowers: perianth bristles 0 (–5), stramineous to pale-brown, 1/2 of to equaling achene length; stamens 3; anthers orangebrown, 0.7–1.5 mm; styles 3-fid. Achenes falling with scales, yellowbrown to medium brown, obovoid to obpyriform, nearly equilaterally trigonous, cross-section circular to slightly compressed, angles obscure or evident, 0.9–1.1 × 0.6–0.75, neck usually very short, finely rugulose at 10–30X, 20 or more low, blunt horizontal ridges in vertical series. Tubercles brown, depressed-pyramidal, often rudimentary, 0.1–0.25 × 0.2–0.3 mm.


Phenology: Fruiting spring–summer (May–Jun).
Habitat: Seasonally wet places on limestone, cedar (juniper) glades, stream beds, prairies, ditches
Elevation: 200–300 m

Discussion

Eleocharis bifida was previously included in E. compressa. A very few specimens of E. compressa var. compressa from the states where E. bifida is known are like E. bifida except for their entire proximal floral scales and evident rhizomes.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis bifida"
yellowbrown +  and medium brown +
cancellate or reticulate +  and rugulose +
trigonous;obovoid;obpyriform +
color +  and texture +
evident +  and obscure +
orangebrown +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
dark-brown +
S. Galen Smith* +, Jeremy J. Bruhl* +, M. Socorro González-Elizondo* +  and Francis J. Menapace* +
S. G. Smith +
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 +
persistent +
circular +  and slightly compressed +
8 cm80 mm <br />0.08 m <br /> (20 cm200 mm <br />0.2 m <br />) +
20 cm200 mm <br />0.2 m <br /> (35 cm350 mm <br />0.35 m <br />) +
compressed +
spongy;hard +
0.7mm;2.3mm +
4-10 times wider than thick +
stramineous distally green +  and stramineous +
Ala. +, Ga. +, Ky. +  and Tenn. +
200–300 m +
membranous +  and thinly papery +
hypogynous +  and subtending +
biconvex +  and trigonous +
Seasonally wet places on limestone, cedar (juniper) glades, stream beds, prairies, ditches +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
ovatelanceolate +
1.5 cm15 mm <br />0.015 m <br /> (?) +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
rugulose +
with (1-)3-6(-30) bristles and/or scales +
Fruiting spring–summer (May–Jun). +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
stramineous;medium brown or red brown or blackish brown +
ascending +  and horizontal +
caudex-like +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
adventitious +
basal +  and proximal +
2-keeled +
1 cm10 mm <br />0.01 m <br /> (?) +
cylindric +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
2.5mm;4mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
with a flower +  and empty +
Eleocharis +
Eleocharis bifida +
Eleocharis (sect. Eleocharis) ser. Eleocharis +
species +
0.1mm;0.25mm +
depressed-pyramidal +
0.2mm +  and 0.3mm +
plant +  and cespitose +