Eleocharis interstincta

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

in J. J. Roemer et al., Syst. Veg. 2: 149. 1817.

Illustrated
Basionym: Scirpus interstinctus Vahl Enum. Pl. 2: 251. 1805
Treatment appears in FNA Volume 23. Treatment on page 119. Mentioned on page 116, 118, 120.

Plants perennial; rhizomes 2–4 mm thick, firm, longer internodes 3–7.5 cm, scales 5 mm, tubers absent. Culms terete, 45–100 cm × (3.2–) 5–9.4 mm, soft to firm, sometimes septate-nodulose proximally, not distally, internally hollow with complete transverse septa, closer together near the spikelet, evident externally; plants never forming filiform, flaccid culms. Leaves: distal leaf-sheaths persistent, membranous to thinly papery, apex acute to acuminate. Spikelets not proliferous, (20–) 40–62 × 4–7 mm; rachilla joints bearing prominent winglike remnants of floral scales; proximal scale empty, amplexicaulous, (3–) 3.5–5 mm; floral scales 115–220, 1–3 per mm of rachilla, stramineous to pale-brown, usually with pale to dark-brown submarginal band, midrib region sometimes greenish, obovate to broadly oblong, (4–) 4.5–5 × 2.8–4 mm, cartilaginous, often membranous toward margins, margins broadly translucent, membranous, apex rounded to subacute. Flowers: perianth bristles 6–8, stramineous, stout, flattened, subequal, exceeding achene, to 2.9 mm, coarsely spinulose; anthers stramineous to reddish, 2.5–5 mm; styles 2-fid or 3-fid. Achenes stramineous to golden-yellow or reddish-brown or gray, obovoid to obpyriform, biconvex or nearly planoconvex, often with abaxial longitudinal ridge, 1.4–1.8 (–2) × 1.1–1.4 mm, markedly sculptured at 10–15X, each face with 23–37 rows of transversely elongated cells, the longitudinal walls separating the cells often prominent, apex with short neck 0.7–0.8 mm wide. Tubercles dark-brown, lamelliform, slightly higher than wide, 0.7–1.1 × 0.5–0.7 mm.


Phenology: Fruiting late spring–winter.
Habitat: Fresh ponds, lakeshores, marshes, springs, ditches, canals
Elevation: 10–500 m

Distribution

V23 181-distribution-map.jpg

Fla., Okla., Tex., Mexico, Central America, e South America

Discussion

Contrary to statements in the literature, sectioning reveals that the culm septa are closer together near the spikelet than in the rest of the culm in both Eleocharis interstincta and E. equisetoides.

Selected References

None.

Lower Taxa

None.
... more about "Eleocharis interstincta"
0.18 cm1.8 mm <br />0.0018 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
stramineous +  and golden-yellow or reddish-brown or gray +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
sculptured +
obovoid;obpyriform biconvex or nearly planoconvex +
constricted +
1.1mm;1.4mm +
stramineous;reddish +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
M. Socorro González-Elizondo +
(Vahl) 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 interstinctus +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
enlarged +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
45 cm450 mm <br />0.45 m <br /> (100 cm1,000 mm <br />1 m <br />) +
filiform +, septate-nodulose +  and terete +
flaccid;soft;firm +
5mm;9.4mm +
Fla. +, Okla. +, Tex. +, Mexico +, Central America +  and e South America +
10–500 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 +
Fresh ponds, lakeshores, marshes, springs, ditches, canals +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
3 cm30 mm <br />0.03 m <br /> (7.5 cm75 mm <br />0.075 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 /> (0.5 cm5 mm <br />0.005 m <br />) +
obovate +  and broadly oblong +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
distinct +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (?) +  and 0.08 cm0.8 mm <br />8.0e-4 m <br /> (?) +
0 cm0 mm <br />0 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
Fruiting late spring–winter. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
amplexicaulous +  and empty +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
stramineous;medium brown or red brown or blackish brown +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
in J. J. Roemer et al., Syst. Veg. +
ascending +  and horizontal +
caudex-like +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
adventitious +
basal +  and proximal +
2-keeled +
5 cm50 mm <br />0.05 m <br /> (?) +
cylindric +
Illustrated +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
4 cm40 mm <br />0.04 m <br /> (6.2 cm62 mm <br />0.062 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 +
3-fid +  and 2-fid +
pale +  and dark-brown +
Eleocharis (sect. Undefined) ser. Mutatae +
Eleocharis interstincta +
Eleocharis subg. Limnochloa +
species +
0.7mm;1.1mm +
slightly higher than wide +
lamelliform +
0.5mm +  and 0.7mm +
stoloniferous +  and rhizomatous +