Cyperus retrofractus

(Linnaeus) Torrey in J. Carey

in J. Carey, Carices North. U.S., 519. 1847.

Common names: Rough flatsedge
IllustratedEndemic
Basionym: Scirpus retrofractus Linnaeus Sp. Pl. 1: 50. 1753
Synonyms: Cyperus dipsaciformis Fernald Cyperus retrofractus var. dipsaciformis (Fernald) Kükenthal Mariscus retrofractus
Treatment appears in FNA Volume 23. Treatment on page 180. Mentioned on page 148, 181.
Revision as of 00:38, 30 July 2020 by imported>Volume Importer
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Herbs, perennial, cespitose. Culms with cormlike bases, sharply trigonous, 25–90 cm, glabrous proximally, minutely scabridulous distally. Leaves V-shaped, 14–40 cm × 3.5–8 mm, (pubescent on adaxial side of midrib). Inflorescences: spikes loose, obtrulloid to obdeltoid (broadest near apex, nearly as long as wide), 20–28 (–34) × (12–) 15–30 mm; rays 4–13, (1–) 4–24 cm (longest ray shorter than bracts), glabrous; bracts 3–12, ascending at 30–45°, flat, 3–25 cm × 3–7 mm; rachilla persistent, wings 0.4–0.6 mm wide, covering 3/4 of mature achene. Spikelets 30–50, proximal one reflexed, distal ones divaricate, linear-lanceoloid, ± terete, (6.5–) 8–10 (–17) × 0.5–0.7 mm; floral scales persistent, 3–6 (–8), appressed, stramineous (suffused with reddish purple), 4–5-ribbed laterally, ovatelanceolate, (4–) 4.4–4.9 (–5.4) × 1.3–1.5 mm; terminal scale not spinose, apex straight, excurved mucronate, or cuspidate. Flowers: anthers 0.7–1.2 mm; styles 1.5–2 mm; stigmas 2–2.5 mm. Achenes brown to brownish black, narrowly oblong, (2.2–) 2.5–3 × 0.6–0.7 mm, base cuneate, apex obtuse, apiculate, surfaces puncticulate.


Phenology: Fruiting summer.
Habitat: Roadsides, pastures, disturbed sites in sandy or clayey soils
Elevation: 0–300 m

Distribution

V23 307-distribution-map.jpg

Ala., Ark., Del., D.C., Ga., Ky., Mo., N.J., N.C., Ohio, Pa., S.C., Tenn., Va.

Discussion

For information concerning nomenclature of Cyperus retrofractus, see J. R. Carter and C. E. Jarvis (1986).

Selected References

None.

Lower Taxa

None.

"shortened" is not a number.

... more about "Cyperus retrofractus"
0.22 cm2.2 mm <br />0.0022 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
brown +  and brownish black +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.6mm;0.7mm +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
straight +
obtuse;cuspidate;mucronate;cuspidate;mucronate;excurved +
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
(Linnaeus) Torrey in J. Carey +
persistent +  and deciduous +
cuneate +
Scirpus retrofractus +
w--shaped +  and keeled +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
3 cm30 mm <br />0.03 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
parallel +  and divergent +
terete +, rolled +  and plicate +
Rough flatsedge +
scabridulous +
trigonous +
25 cm250 mm <br />0.25 m <br /> (90 cm900 mm <br />0.9 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
Ala. +, Ark. +, Del. +, D.C. +, Ga. +, Ky. +, Mo. +, N.J. +, N.C. +, Ohio +, Pa. +, S.C. +, Tenn. +  and Va. +
0–300 m +
0.49 cm4.9 mm <br />0.0049 m <br /> (0.54 cm5.4 mm <br />0.0054 m <br />) +
0.44 cm4.4 mm <br />0.0044 m <br /> (0.49 cm4.9 mm <br />0.0049 m <br />) +
ovatelanceolate +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
Roadsides, pastures, disturbed sites in sandy or clayey soils +
subumbellate +  and capitate +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
14 cm140 mm <br />0.14 m <br /> (?) +  and 40 cm400 mm <br />0.4 m <br /> (?) +
v--shaped +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
Fruiting summer. +
2-3(-4)-carpellate +
antrorse +  and extrorse +
3 (?) +  and 1 (?) +
in J. Carey, Carices North. U.S., +
continuous +, articulate +, winged +  and wingless +
conspicuous +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
unequal +
4 +  and 13 +
4 cm40 mm <br />0.04 m <br /> (24 cm240 mm <br />0.24 m <br />) +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
Illustrated +  and Endemic +
2.8 cm28 mm <br />0.028 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
2 cm20 mm <br />0.02 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
obtrulloid;obdeltoid +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
30 +  and 50 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
2-3-fid +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Cyperus dipsaciformis +, Cyperus retrofractus var. dipsaciformis +  and Mariscus retrofractus +
Cyperus retrofractus +
Cyperus subg. Cyperus +
species +
tuberous +, stoloniferous +  and rhizomatous +
herb +  and cespitose +
0.4mm +  and 0.6mm +