Cyperus niger

Ruiz & Pavón

Fl. Peruv. 1: 47. 1798.

Illustrated
Synonyms: Cyperus diandrus var. castaneus S. Watson Cyperus melanostachyus Kunth Cyperus niger var. castaneus (S. Watson) Kükenthal
Treatment appears in FNA Volume 23. Mentioned on page 161.

Herbs, perennial, rhizomatous. Culms solitary or close together, trigonous, 5–40 (–95) cm, glabrous. Leaves (2–) 3–7, broadly V-shaped, 3–20 (–30) cm × 1.5–3 mm. Inflorescences: spikes loosely to densely ovoid to hemispheric, 7–16 mm diam.; rachis 1–2 mm, or absent; rays 1–2, 3–45 mm; if rays absent, inflorescence sessile, dense, 6–20 mm diam; bracts 2–3, horizontal to reflexed downward, broadly V-shaped, 1–15 cm × 1–3 mm. Spikelets (3–) 5–25 (–60), linear to oblong-linear, (3–) 5–9 × 1.8–2.3 mm; floral scales 4–18, closely imbricate, chestnut-brown, black, or brown, medially green or greenish brown, laterally ribless, medially 2 (–3) -ribbed, distinctly 2-keeled basally, ovate to orbiculate, 1.5–2.1 × 1.4–2.2 mm, apex obtuse. Flowers: stamens 2; anthers 0.6–0.8 mm, connectives not prolonged; styles 0.4–0.6 mm; stigmas 0.7–2.1 mm. Achenes brown, ellipsoid, 1.2–1.4 × 0.6–0.8 mm, network of ridges forming isodiametric or square cells, slightly stipitate, apex apiculate, surfaces minutely punctate.


Phenology: Fruiting summer.
Habitat: Swamps, ditches, wet pastures, seeps in montane forests
Elevation: 0–1200 m

Distribution

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Ariz., Calif., N.Mex., Okla., Tex., Mexico, Central America, South America

Discussion

Six varieties (Cyperus niger var. niger, var. castaneus, var. robustus, var. lorentizianus, var. intricate-ramosus, and var. pseudo-elegantulus) were recognized by G. Kükenthal (1935–1936). Based on field observations and measurements of hundreds of collections from Mexico, where the species is most plentiful, it does not seem possible to recognize any of the infraspecific taxa (G. C. Tucker 1983, 1994; G. C. Tucker and R. McVaugh 1993).

Selected References

None.

Lower Taxa

None.

"shortened" is not a number.

... more about "Cyperus niger"
0.12 cm1.2 mm <br />0.0012 m <br /> - 0.14 cm1.4 mm <br />0.0014 m <br /> +
ellipsoid +
0.6mm;0.8mm +
0.06 cm0.6 mm <br />6.0e-4 m <br /> - 0.08 cm0.8 mm <br />8.0e-4 m <br /> +
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Ruiz & Pavón +
persistent +  and deciduous +
decurrent +
Undefined subg. Pycreus +
w--shaped +  and keeled +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
1 cm10 mm <br />0.01 m <br /> - 15 cm150 mm <br />0.15 m <br /> +
downward +, horizontal +  and reflexed +
v--shaped +
0.1 cm1 mm <br />0.001 m <br /> - 0.3 cm3 mm <br />0.003 m <br /> +
parallel +  and divergent +
terete +, rolled +  and plicate +
square +  and isodiametric +
not prolonged +
close +  and solitary +
scabridulous +
trigonous +
5 cm50 mm <br />0.05 m <br /> - 40 cm400 mm <br />0.4 m <br /> +
Ariz. +, Calif. +, N.Mex. +, Okla. +, Tex. +, Mexico +, Central America +  and South America +
0–1200 m +
greenish brown +, green +, brown +, black +  and chestnut-brown +
0.15 cm1.5 mm <br />0.0015 m <br /> - 0.21 cm2.1 mm <br />0.0021 m <br /> +
ovate +  and orbiculate +
0.14 cm1.4 mm <br />0.0014 m <br /> - 0.22 cm2.2 mm <br />0.0022 m <br /> +
hypogynous +  and subtending +
biconvex +  and trigonous +
Swamps, ditches, wet pastures, seeps in montane forests +
0.6 cm6 mm <br />0.006 m <br /> - 2 cm20 mm <br />0.02 m <br /> +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
20 cm200 mm <br />0.2 m <br /> - 30 cm300 mm <br />0.3 m <br /> +
3 cm30 mm <br />0.03 m <br /> - ? +  and 20 cm200 mm <br />0.2 m <br /> - ? +
v--shaped +
0.15 cm1.5 mm <br />0.0015 m <br /> - 0.3 cm3 mm <br />0.003 m <br /> +
with - 1-3-6 - -30 bristles and/or scales +
Fruiting summer. +
2-3 - -4-carpellate +
antrorse +  and extrorse +
3 - ? +  and 1 - ? +
nearly +  and wingless +
unequal +
1 +  and 2 +
0.3 cm3 mm <br />0.003 m <br /> - 4.5 cm45 mm <br />0.045 m <br /> +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
Illustrated +
0.7 cm7 mm <br />0.007 m <br /> - 1.6 cm16 mm <br />0.016 m <br /> +
ovoid;hemispheric +
loosely spicate +  and more or less digitate +
linear +  and oblong-linear +
0.3 cm3 mm <br />0.003 m <br /> - 0.5 cm5 mm <br />0.005 m <br /> +
0.5 cm5 mm <br />0.005 m <br /> - 0.9 cm9 mm <br />0.009 m <br /> +
5 +  and 25 +
1.8mm;2.3mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.07 cm0.7 mm <br />7.0e-4 m <br /> - 0.21 cm2.1 mm <br />0.0021 m <br /> +
2-3-fid +
0.04 cm0.4 mm <br />4.0e-4 m <br /> - 0.06 cm0.6 mm <br />6.0e-4 m <br /> +
Cyperus diandrus var. castaneus +, Cyperus melanostachyus +  and Cyperus niger var. castaneus +
Cyperus niger +
Cyperus subg. Pycreus +
species +