Eleocharis pachycarpa

E. Desvaux in C. Gay

in C. Gay, Fl. Chil. 6: 174. 1853.

IntroducedIllustrated
Treatment appears in FNA Volume 23. Treatment on page 91. Mentioned on page 62, 68, 92.

Plants perennial, forming dense clumps, often stoloniferous. Rhizomes present, caudexlike, mostly concealed by crowded culms, vertical or ascending, 2 mm thick; internodes very short, scales disintegrating to fibers, 4 mm, papery. Culms erect to ascending or arching, acutely quadrangular, deeply sulcate, 7–50 cm × 0.3–0.5 mm, smooth, firm. Leaves: distal leaf-sheaths persistent, proximally brown or reddish, distally stramineous to green, thickly membranous, apex acute or subacute. Spikelets: basal spikelets absent; often proliferous, ovoid, terete, 3–10 × 2–3 mm, apex acute; proximal scale empty, amplexicaulous, similar to floral scales; subproximal scale with a flower; floral scales spiraled, 8–15, 4 per mm of rachilla, orangebrown, midrib region broadly stramineous or like flanks, ovate, 2–3 × 1.2–2 mm, membranous, midrib evident to prominent, apex acute (to rounded). Flowers: perianth bristles 6 or fewer, stramineous, unequal, some or most equaling achene, spinules obscure, sparse, retrorse, sharply acute. Stamens 3; anthers 1.2–1.5 mm. Styles 3-fid. Achenes stramineous, broadly obpyriform, equilaterally trigonous, angles evident, blunt, 0.9–1.1 × 0.7–0.9 mm, apex nearly truncate, smooth or obscurely papillose or rugulose at 20X. Tubercles stramineous, pyramidal, trigonous, usually acute, proximally trilobed, the lobes decurrent on achene, 0.5–0.9 × 0.7–0.9 mm.


Phenology: Fruiting late spring–summer.
Habitat: Fresh shores, streambeds, groundwater seeps
Elevation: 100–1400 m

Distribution

V23 129-distribution-map.jpg

Introduced; Calif., Nev., South America (Argentina), South America (Chile), in Australia

Discussion

H. K. Svenson (1957) placed Eleocharis pachycarpa in ser. Sulcatae Svenson. Contrary to his statement that perianth bristles are often lacking, they are present in all of the specimens we have seen. Superficially similar to E. bolanderi, from which it may readily be distinguished by its oblique leaf sheath summits, 4-angled culms, pyramidal tubercles, and often proliferating spikelets. The earliest North American specimen we have seen was collected in 1919 in Tuolumne County, California.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis pachycarpa"
with longitudinal rows +, smooth +  and honeycomb-reticulate +
stramineous +
smooth +  and markedly sculptured +
trigonous;obpyriform +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
0.7mm;0.9mm +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
rugulose +, papillose +  and smooth +
Jeremy J. Bruhl +  and S. Galen Smith +
E. Desvaux in C. Gay +
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 +
7 cm70 mm <br />0.07 m <br /> (50 cm500 mm <br />0.5 m <br />) +
erect +  and ascending or arching +
quadrangular +
0.3mm;0.5mm +
reddish distally stramineous +  and green +
Calif. +, Nev. +, South America (Argentina) +, South America (Chile) +  and in Australia +
100–1400 m +
papery +  and membranous +
hypogynous +  and subtending +
biconvex +  and trigonous +
Fresh shores, streambeds, groundwater seeps +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
decurrent +
0.7mm;0.9mm +
evident +  and prominent +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
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 late spring–summer. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
amplexicaulous +  and empty +
stramineous;medium brown or red brown or blackish brown +
in C. Gay, Fl. Chil. +
ascending +  and vertical +
caudex-like +
2 cm20 mm <br />0.02 m <br /> (?) +
adventitious +
disintegrating +
basal +  and proximal +
2-keeled +
4 cm40 mm <br />0.04 m <br /> (?) +
cylindric +
Introduced +  and Illustrated +
stoloniferous +
proliferating +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
terete;ovoid +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
Eleocharis +
Eleocharis pachycarpa +
Eleocharis (sect. Eleocharis) ser. Tenuissimae +
species +
acute +, trigonous +  and pyramidal +