familyCyperaceae
genusCyperus
subgenusCyperus subg. Cyperus
speciesCyperus cephalanthus

Cyperus cephalanthus

Torrey & Hooker

Ann. Lyceum Nat. Hist. New York. 3: 431. 1836.

Gordon C. Tucker*, Brian G. Marcks*, J. Richard Carter *
Illustrated
Synonyms: Cyperus laetus var. cephalanthus (Torrey & Hooker) Kükenthal
Treatment appears in FNA Volume 23. Mentioned on page 180.
Please click on the illustration for a higher resolution version.
Illustrator: Yevonn Wilson-Ramsey

Copyright: Flora of North America Association

Herbs, perennial, rhizomatous. Culms trigonous, 40–70 (–100) cm × 2–3 mm, scabrid or hirtellate, either immediately proximal to apex or over distal 1/2 of culm. Leaves flat, 30–80 cm × 4–10 mm, scabrid on margins, ribs on abaxial surface. Inflorescences: spikes ovoid, 12–20 × 13–18 mm; rays 3–6, 4–10 (–16) cm, glabrous; bracts 3–5, ± horizontal to reflexed, 3–12 (–36) cm × 0.4–3 (–5) mm, scabrid like leaves; rachilla deciduous, essentially wingless or wings inconspicuous, hyaline, 0.1 (–0.2) mm wide. Spikelets 25–50 (–80), oblong, quadrangular-compressed, 5–10 × 2.5–3.5 mm; floral scales deciduous, 4–10 (–14), marginally clear, laterally brownish to clear distally, or light-brown or reddish-brown, blunt, laterally 3 (–4) -ribbed, ovatelanceolate, 2.5–3 × (1.2–) 1.4–2 mm, often erose apically, apex acute to obtuse, entire or emarginate. Flowers: anthers 0.4–0.6 mm; styles 0.8–1.2 mm; stigmas 2 mm. Achenes brown to reddish-brown, ± stipitate, ellipsoid, 1.2 × 0.5–0.6 mm, apex obtuse, scarcely to distinctly apiculate, surfaces puncticulate.


Phenology: Fruiting summer.
Habitat: Wet prairies
Elevation: 0–50 m

Distribution

V23 306-distribution-map.jpg

La., Okla., Tex., South America (Argentina), South America (Brazil), South America (Paraguay), South America (Uruguay)

Discussion

The combination of spreading floral scales and scabrid culms separates this rather uncommon species from any others occurring in its range. The scarcity of Cyperus cephalanthus in the United States and its disjunct distribution suggest it might be naturalized rather than native. It was collected early in the nineteenth century in Louisiana, and the amphitropical distribution is not without parallel in the genus (cf. 12. C. eragrostis).

Cyperus cephalanthus has been treated as a variety of the widespread, polymorphic South American C. laetus (G. Kükenthal 1935–1936). Recognition of C. cephalanthus as a species follows recent American floristic practice.

Selected References

None.

Lower Taxa

None.

"shortened" is not a number.

... more about "Cyperus cephalanthus"
RDF feed
Achene architecture
stipitate +
Achene coloration
brown +  and reddish-brown +
Achene length
1.2 cm12 mm <br />0.012 m <br /> (?) +
Achene life cycle
mature +
Achene shape
ellipsoid +
Achene width
0.5mm;0.6mm +
Anther fixation
basifixed +
Anther some measurement
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Apex architecture or shape
emarginate +  and entire +
Apex shape
obtuse;scarcely distinctly apiculate +
Author
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Authority
Torrey & Hooker +
Base duration
persistent +  and deciduous +
Base shape
decurrent +
Blade presence
absent +
Blade prominence or shape
flat +
Blade shape
w--shaped +  and keeled +
Bract architecture
glumaceous +  and foliaceous +
Bract arrangement
2-ranked +  and arranged +
Bract atypical length
12 cm120 mm <br />0.12 m <br /> (36 cm360 mm <br />0.36 m <br />) +
Bract atypical width
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Bract length
3 cm30 mm <br />0.03 m <br /> (12 cm120 mm <br />0.12 m <br />) +
Bract orientation
less horizontal +  and reflexed +
Bract quantity
3;5 +
Bract width
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Branch atypical quantity
3 (4) +
Branch quantity
2;3 +
Bristle atypical quantity
6;30 +
Bristle quantity
3;6 +
Cauline leaf architecture or shape
folded +
Cauline leaf arrangement
parallel +  and divergent +
Cauline leaf arrangement or course or shape
linear +
Cauline leaf orientation
Ascending (?) +
Cauline leaf prominence or shape
flat +
Cauline leaf shape
terete +, rolled +  and plicate +
Culm architecture or arrangement or growth form
not +  and solitary +
Culm atypical length
70 cm700 mm <br />0.7 m <br /> (100 cm1,000 mm <br />1 m <br />) +
Culm length
40 cm400 mm <br />0.4 m <br /> (70 cm700 mm <br />0.7 m <br />) +
Culm position
proximal +
Culm pubescence
glabrous +
Culm pubescence or relief
hirtellate +  and scabrid +
Culm relief
scabridulous +
Culm shape
trigonous +
Culm width
2mm;3mm +
Distal scale architecture
empty +
Distribution
La. +, Okla. +, Tex. +, South America (Argentina) +, South America (Brazil) +, South America (Paraguay) +  and South America (Uruguay) +
Elevation
0–50 m +
Embryo position
basal +
Endosperm quantity
abundant +
Floral scale architecture or relief
erose +
Floral scale architecture or shape
3(-4)-ribbed +
Floral scale arrangement
distichous +
Floral scale atypical quantity
10 (14) +
Floral scale atypical width
0.12 cm1.2 mm <br />0.0012 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
Floral scale coloration
laterally brownish +  and clear distally +
Floral scale duration
deciduous +
Floral scale length
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Floral scale quantity
4 (10) +
Floral scale shape
ovatelanceolate +  and blunt +
Floral scale width
0.14 cm1.4 mm <br />0.0014 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flower position
hypogynous +  and subtending +
Flower quantity
single +
Flower reproduction
bisexual +
Fruits achene shape
biconvex +  and trigonous +
Habitat
Wet prairies +
Illustration
Present +
Illustration copyright
Flora of North America Association +
Illustrator
Yevonn Wilson-Ramsey +
Inflorescence architecture
subumbellate +  and capitate +
Inflorescence position
pseudolateral +
Inflorescence position or structure subtype
terminal +
Inflorescences panicle architecture
pseudoumbel +
Inflorescences panicle development
modified +
Involucral-bract architecture or shape
leaflike +
Involucral-bract arrangement
arranged +
Involucral-bract orientation
spreading +  and erect +
Involucral-bract quantity
1;22 +
Leaf arrangement
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
Leaf length
30 cm300 mm <br />0.3 m <br /> (?) +  and 80 cm800 mm <br />0.8 m <br /> (?) +
Leaf position
basal +
Leaf prominence or shape
flat +
Leaf pubescence or relief
scabrid +
Leaf shape
like +
Leaf width
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Ligule presence
absent +
Locule quantity
1 +
Margin fusion
fused +
Number of lower taxa
0 +
Perianth life cycle
falling +
Perianth presence
absent +
Perianth quantity
with (1-)3-6(-30) bristles and/or scales +
Pericarp width
thin +
Phenology
Fruiting summer. +
Pistil architecture
2-3(-4)-carpellate +
Pistil fusion
fused +
Pistil quantity
1 +
Prickle orientation
antrorse +  and extrorse +
Prophyll architecture
pistillate +
Prophyll atypical quantity
0 (3) +
Prophyll position
subtending +
Prophyll quantity
3 (?) +  and 1 (?) +
Publication title
Ann. Lyceum Nat. Hist. New York. +
Publication year
1836 +
Rachillum architecture
wingless +
Rachillum duration
deciduous +
Rachillum life cycle
falling +
Rachis prominence
conspicuous +
Ray arrangement
singly +
Ray atypical some measurement
10 cm100 mm <br />0.1 m <br /> (16 cm160 mm <br />0.16 m <br />) +
Ray length
unequal +
Ray pubescence
glabrous +
Ray quantity
3 +  and 6 +
Ray some measurement
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Reference
None +
Root derivation
adventitious +
Root texture
fibrous +
Scale architecture
empty +
Scale arrangement
distichous +
Scale atypical quantity
6 (30) +
Scale position
basal +  and proximal +
Scale quantity
0;76 +
Scale reproduction
fertile +
Scale shape
cylindric;compressed +
Seed quantity
1 +
Sheath shape
cylindric +
Source xml
https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V23/V23 306.xml +
Special status
Illustrated +
Spike architecture or fragility
loose +
Spike density
dense +
Spike length
1.2 cm12 mm <br />0.012 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Spike quantity
single +
Spike shape
ovoid +
Spike width
1.3 cm13 mm <br />0.013 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
Spikelet architecture
spicate +
Spikelet architecture or arrangement or growth form
solitary +
Spikelet arrangement
arranged +
Spikelet atypical quantity
50 (80) +
Spikelet length
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Spikelet life cycle
falling +
Spikelet quantity
25 +  and 50 +
Spikelet shape
quadrangular-compressed;oblong +
Spikelet width
2.5mm;3.5mm +
Stamen atypical quantity
1 (3) +
Stamen fusion
distinct +
Stamen quantity
3 +
Stem architecture
septate +, hollow +  and solid +
Stem shape
compressed +, terete +  and trigonous +
Stigma quantity
3 +
Stigma relief
papillate +
Stigma some measurement
2 cm20 mm <br />0.02 m <br /> (?) +
Style architecture or shape
undivided +
Style arrangement or course or shape
linear +
Style shape
2-3-fid +
Style some measurement
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Surface coloration or relief
puncticulate +
Synonyms
Cyperus laetus var. cephalanthus +
Taxon family
Cyperaceae +
Taxon name
Cyperus cephalanthus +
Taxon parent
Cyperus subg. Cyperus +
Taxon rank
species +
Testa fusion
free +
Testa width
thin +
Volume
Volume 23 +
Whole organism architecture
rhizomatous +
Whole organism duration
perennial +
Whole organism growth form
herb +
Wing coloration
hyaline +
Wing prominence
inconspicuous +
Wing width
0.1 +, 0.1mm +  and 0.2mm +
X chromosome quantity
5;100 +