Cyperus aggregatus

(Willdenow) Endlicher

Cat. Horti Vindob. 1: 93. 1842.

Illustrated
Basionym: Mariscus aggregatus Willdenow Enum. Pl. 1: 70. 1809 Cyperus cayennensis (Lamarck) Britton 1907 Cyperus flavus (Vahl) Nees 1847
Synonyms: Cyperus flavus var. aggregatus (Willdenow) Kükenthal Cyperus flavus var. laevis Kükenthal Kyllinga cayennensis Baldwin Kyllinga squarrosa Vahl Mariscus flavus Kunth Mariscus laevis
Treatment appears in FNA Volume 23. Mentioned on page 188.

Herbs, perennial, cespitose, rhizomatous. Culms trigonous, 20–100 cm × 0.8–2.5 mm, glabrous. Leaves 5–10, V-shaped to flanged V-shaped, 10–70 (–90) cm × 2–7 mm, margins and midribs scabridulous or glabrous. Inflorescences: spikes 1 (–6), densely cylindric, 6–30 × 5–11 mm; rays 3–12, 0.4–5 (–7) cm; rays and rachis glabrous; usually only 1–2 spikes of inflorescence on elongate rays, other spikes sessile or nearly so; bracts 4–7, horizontal to slightly ascending, 1–16 cm × 0.5–4 mm; rachilla deciduous, wings persistent, 0.5 mm wide. Spikelets 20–80, ellipsoid, roughly quadrangular, 3–5 × 1–1.4 mm; floral scales 1–2 (–4), appressed, stramineous to golden brown, often red-speckled, medially greenish, 9-ribbed, elliptic to ovate, 2.4–3.4 × 1.8–2.6 mm, apex obtuse. Flowers: anthers 0.4–0.6 mm; styles 0.7–1.1 mm; stigmas 1.4–2.1 mm. Achenes dark-brown to reddish-brown, sessile, broadly ellipsoid, 1.8–2.1 × 0.8–1 mm, apex apiculate, surfaces glabrous to finely puncticulate.


Phenology: Fruiting mid summer–fall (Jul–Oct).
Habitat: Dry roadsides, pastures, thickets
Elevation: 0–500 m

Distribution

V23 325-distribution-map.jpg

Introduced; Ariz., La., Miss., N.J., N.Mex., Oreg., Pa., Tex., Mexico, Central America, South America, Australia

Discussion

The records of Cyperus aggregatus in New Jersey, Oregon, and Pennsylvania represent introductions from ballast.

The closely related Mexican and Central American Cyperus regiomontanus Britton has been collected once as an adventive or waif in southern California. It is distinguished from C. aggregatus by its silvery green, subulate-lanceolate spikelets and achenes that are only 0.4–0.6 mm wide.

Selected References

None.

Lower Taxa

None.
... more about "Cyperus aggregatus"
dark-brown +  and reddish-brown +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
ellipsoid +
0.8mm;1mm +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
(Willdenow) Endlicher +
shortened +
persistent +  and deciduous +
decurrent +
Mariscus aggregatus +, Cyperus cayennensis +  and Cyperus flavus +
w--shaped +  and keeled +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
1 cm10 mm <br />0.01 m <br /> (16 cm160 mm <br />0.16 m <br />) +
horizontal +  and slightly ascending +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
parallel +  and divergent +
terete +, rolled +  and plicate +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
scabridulous +
trigonous +
0.8mm;2.5mm +
Ariz. +, La. +, Miss. +, N.J. +, N.Mex. +, Oreg. +, Pa. +, Tex. +, Mexico +, Central America +, South America +  and Australia +
0–500 m +
greenish +, red-speckled +, stramineous +  and golden brown +
deciduous +  and persistent +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.34 cm3.4 mm <br />0.0034 m <br />) +
elliptic +  and ovate +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
Dry roadsides, pastures, thickets +
subumbellate +  and capitate +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
70 cm700 mm <br />0.7 m <br /> (90 cm900 mm <br />0.9 m <br />) +
10cm +  and 70cm +
v--shaped +, v-shaped +  and flanged +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
scabridulous +
scabridulous +
with (1-)3-6(-30) bristles and/or scales +
Fruiting mid summer–fall (Jul–Oct). +
2-3(-4)-carpellate +
antrorse +  and extrorse +
3 (?) +  and 1 (?) +
Cat. Horti Vindob. +
continuous +, articulate +, winged +  and wingless +
conspicuous +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
unequal +
3 +  and 12 +
elongate +
0.4 cm4 mm <br />0.004 m <br /> (5 cm50 mm <br />0.05 m <br />) +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
Illustrated +
nearly +  and sessile +
0.6 cm6 mm <br />0.006 m <br /> (3 cm30 mm <br />0.03 m <br />) +
cylindric +
0.5 cm5 mm <br />0.005 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
20 +  and 80 +
quadrangular;ellipsoid +
1mm;1.4mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
2-3-fid +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
Cyperus flavus var. aggregatus +, Cyperus flavus var. laevis +, Kyllinga cayennensis +, Kyllinga squarrosa +, Mariscus flavus +  and Mariscus laevis +
Cyperus aggregatus +
Cyperus subg. Cyperus +
species +
herb +  and cespitose +
persistent +