Cyperus giganteus

Vahl

Enum. Pl. 2: 364. 1805.

Common names: Mexican papyrus
IntroducedIllustrated
Treatment appears in FNA Volume 23. Treatment on page 173. Mentioned on page 147, 167, 174.

Herbs, perennial, rhizomatous, stout. Culms roundly trigonous, 200–350 cm × 15–50 mm, glabrous. Leaves bladeless. Inflorescences: spikes loosely cylindric, 15–40 × 8–16 mm; rays 5–8, ascending to erect, stiff,20–30 cm; 2d order rays 5–15 cm; bracts 10–12, ascending at 30–60°, flat, (8–) 20–45 cm × 4–12 mm; 2d order bracts (5–) 15–25 cm × 1.5–5 mm; rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 mm wide. Spikelets (15–) 50–80, slightly compressed, linear, ± quadrangular, 5–12 × 0.6–1.4 mm; floral scales 8–20, appressed, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse. Flowers: anthers 0.7–1 mm (connective prolonged beyond anther as red subulate appendage 0.2–0.5 mm, its apex sometimes setose); styles 0.2–0.5 mm; stigmas (0.8–) 1.2–1.8 mm. Achenes pale-brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate.


Phenology: Fruiting summer.
Habitat: Stream banks, marshes
Elevation: 0–10 m

Distribution

V23 288-distribution-map.jpg

Introduced; La., Tex., Mexico, West Indies, Central America, South America

Discussion

Cyperus giganteus was erroneously reported from Florida, a misidentification of C. papyrus (R. R. Haynes and A. Lasseigne 1969).

Recently, some nurseries specializing in water plants have begun to offer C. giganteus under the name “Mexican papyrus.” Escaped cultivated plants may be expected in southeastern and southwestern United States.

Selected References

None.

Lower Taxa

None.

"shortened" is not a number.

... more about "Cyperus giganteus"
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.4mm;0.5mm +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
acute;obtuse +
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
persistent +  and deciduous +
decurrent +
w--shaped +  and keeled +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
15 cm150 mm <br />0.15 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
parallel +  and divergent +
terete +, rolled +  and plicate +
Mexican papyrus +
200 cm2,000 mm <br />2 m <br /> (350 cm3,500 mm <br />3.5 m <br />) +
scabridulous +
trigonous +
15mm;50mm +
La. +, Tex. +, Mexico +, West Indies +, Central America +  and South America +
0–10 m +
deciduous +  and persistent +
hypogynous +  and subtending +
biconvex +  and trigonous +
Stream banks, marshes +
subumbellate +  and capitate +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
white +  and hyaline +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
Fruiting summer. +
2-3(-4)-carpellate +
antrorse +  and extrorse +
3 (?) +  and 1 (?) +
continuous +, articulate +, winged +  and wingless +
0.3mm +  and 0.4mm +
conspicuous +
unequal +
ascending +  and erect +
5 +  and 8 +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
Introduced +  and Illustrated +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
cylindric +
0.8 cm8 mm <br />0.008 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
50 +  and 80 +
quadrangular;compressed +
0.6mm;1.4mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
papillate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
2-3-fid +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Undefined subg. Chlorocyperus +, Cyperus subg. Mariscus +  and Undefined subg. Papyrus +
Cyperus giganteus +
Cyperus subg. Cyperus +
species +