Eleocharis montevidensis

Kunth

Enum. Pl. 2: 144. 1837.

Illustrated
Synonyms: Eleocharis arenicola Torrey Eleocharis montana subsp. montevidensis (Kunth) Osten Eleocharis palmeri Svenson
Treatment appears in FNA Volume 23. Treatment on page 80. Mentioned on page 66, 68, 79, 81, 82, 83.

Plants perennial, mat-forming; rhizomes evident, long, 0.7–2 mm thick, firm, cortex persistent, longer internodes 1–2 cm, scales often fugaceous, 6–8 mm, membranous, not fibrous. Culms terete or cross-section elliptic or rectangular, with 5–10 blunt ridges when dry, 25–50 cm × 0.5–1.2 mm, firm to hard, spongy. Leaves: distal leaf-sheaths persistent, not splitting, mostly proximally dark red, distally red to brown or green, thinly papery, apex usually redbrown, often callose, subtruncate to obtuse, tooth usually present on some or all culms, to 0.9 mm. Spikelets usually ovoid or ellipsoid to subcylindric, rarely lanceoloid, 4–12 × (1.5–) 2–3 mm, apex rounded to acute; proximal scale amplexicaulous or clasping over 3/4 of culm, entire; subproximal scale empty or with flower; floral scales appressed in fruit, 30–100, 6–10 per mm of rachilla, orangebrown, midrib regions often greenish, oblong to ovate, 1.5–2.5 × 1–1.5 mm, apex entire, broadly rounded, sometimes acute in distal part of spikelet, usually horizontally wrinkled and recurved, often carinate in distal part of spikelet. Flowers: perianth bristles 5–6 (–7), stramineous to medium brown, stout, often unequal, much shorter than to equaling achene, rarely all rudimentary; stamens 3; anthers dark yellow to stramineous, 0.8–1.5 mm; styles 3-fid or some 2-fid. Achenes falling with scales, dark-brown, obovoid to obpyriform, compressed trigonous, angles evident to obscure, 0.7–1 × 0.65–0.8 mm, neck absent to sometimes long, finely rugulose at 10–30X, over 20 horizontal ridges in vertical series, and/or minutely cancellate at 20–30X. Tubercles brown to whitish, pyramidal, as high as wide or sometimes greatly depressed, (0.1–) 0.25–0.3 × 0.2–0.3 mm. 2n = 20.


Phenology: Fruiting spring–fall.
Habitat: Wet soil, fresh ponds, lakes, streams, springs, seeps, marshes, ditches, grasslands
Elevation: 0–2300 m

Distribution

V23 107-distribution-map.jpg

Ala., Ariz., Calif., Fla., Kans., La., Miss., N.Mex., N.C., Okla., S.C., Tex., Mexico, South America

Discussion

The name Eleocharis montana was long misapplied to E. montevidensis. The type of E. palmeri, recognized as a species (H. K. Svenson 1957), is indistinguishable from specimens of E. montevidensis. Eleocharis montevidensis is extremely variable; the broadly rounded, usually wrinkled and recurved floral scales are diagnostic. Achenes often fail to form. Eleocharis montevidensis is apparently closely related to E. parishii, in which the floral scales are less densely placed on the rachilla and acute to rounded, and the spikelets are narrowly lanceoloid to cylindric. In the absence of achenes and rhizomes, some specimens of E. montevidensis are easily mistaken for E. tricostata.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis montevidensis"
cancellate or reticulate +  and rugulose +
trigonous;compressed;obovoid;obpyriform +
color +  and texture +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
evident +  and obscure +
0.65mm;0.8mm +
dark yellow;stramineous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
wrinkled +
S. Galen Smith* +, Jeremy J. Bruhl* +, M. Socorro González-Elizondo* +  and Francis J. Menapace* +
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 +
rectangular +  and elliptic +
0 cm0 mm <br />0 m <br /> (100 cm1,000 mm <br />1 m <br />) +
0.3mm;5mm +
distally red +  and brown or green +
Ala. +, Ariz. +, Calif. +, Fla. +, Kans. +, La. +, Miss. +, N.Mex. +, N.C. +, Okla. +, S.C. +, Tex. +, Mexico +  and South America +
0–2300 m +
membranous +  and thinly papery +
hypogynous +  and subtending +
biconvex +  and trigonous +
Wet soil, fresh ponds, lakes, streams, springs, seeps, marshes, ditches, grasslands +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
oblong +  and ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 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–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
clasping +  and amplexicaulous +
stramineous;medium brown or red brown or blackish brown +
ascending +  and horizontal +
caudex-like +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
25cm;50cm +
spongy;firm;hard +
0.5mm;1.2mm +
adventitious +
fugaceous +
basal +  and proximal +
2-keeled +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
not fibrous +  and membranous +
cylindric +
Illustrated +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
lanceoloid;ellipsoid;subcylindric +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
2-fid +, some +  and 3-fid +
with flower +  and empty +
Eleocharis arenicola +, Eleocharis montana subsp. montevidensis +  and Eleocharis palmeri +
Eleocharis montevidensis +
Eleocharis (sect. Eleocharis) ser. Eleocharis +
species +
0 cm0 mm <br />0 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.025 cm0.25 mm <br />2.5e-4 m <br />) +
brown;whitish +
0.25mm;0.3mm +
depressed +  and pyramidal +
0.2mm +  and 0.3mm +
plant +  and mat-forming +