Cyperus retrorsus

Chapman

Bot. Gaz. 3: 17. 1878.

Illustrated
Basionym: Mariscus cylindricus Elliott Sketch Bot. S. Carolina 1: 74. 1816 Cyperus cylindricus (Elliott) Britton 1879
Synonyms: Mariscus retrorsus (Chapman) C. B. Clarke
Treatment appears in FNA Volume 23. Treatment on page 187. Mentioned on page 150, 183, 185.

Herbs, perennial, cespitose, shortly rhizomatous. Culms trigonous, 20–50 (–85) cm × 1–2 (–4) mm, glabrous. Leaves 3–6 (–10), 10–40 (–55) cm × 1.5–4 (–5) mm, V to inversely W-shaped. Inflorescence: spike 1, densely oblong-ovoid often with small basal branches, 8–16 × 4–12 (–16) mm; rays 4–8 (–11), 0.5–3.5 (–8.5) cm; bracts (3–) 4–6 (–10), ascending at (30–) 45°, flat to broadly V-shaped, (4–) 14–30 (–55) cm × 1–5 mm, scabridulous along margins only; rachilla deciduous, wings persistent, 0.2–0.3 mm wide. Spikelets 40–120, oblong-lanceoloid, subterete, 2.2–4 (–4.5) × 0.8–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 2–5, appressed, brown to stramineous, or fuscous and lustrous, medially greenish and 1 (–3) -ribbed, laterally greenish to yellowish white and 3–4-ribbed, oblong to oblong-lanceolate, 1.8–2.5 × 1–1.5 mm, subcoriacous. Flowers: anthers 0.3–0.5 mm; styles 0.5–0.8 mm; stigmas 0.6–0.9 mm. Achenes brown, oblongellipsoid, 1.2–1.7 × 0.5–0.6 mm, base cuneate, apex subacute, surfaces papillose.


Phenology: Fruiting summer (Jun–Aug).
Habitat: Open woods and thickets in moist to dry, sandy soils
Elevation: 0–1000 m

Distribution

V23 323-distribution-map.jpg

Ala., Ark., Del., D.C., Fla., Ga., La., Md., Miss., Mo., N.J., N.Y., N.C., Okla., S.C., Tenn., Tex., Va., Mexico (Tamaulipas)

Discussion

Cyperus retrorsus was reported in Indiana (M. L. Horvat 1941); we have been unable to confirm the report.

Selected References

None.

Lower Taxa

None.

"shortened" is not a number.

... more about "Cyperus retrorsus"
0.12 cm1.2 mm <br />0.0012 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
flattened;trigonous +
0.5mm;0.6mm +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
subacute +
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Chapman +
persistent +  and deciduous +
cuneate +
Mariscus cylindricus +  and Cyperus cylindricus +
w--shaped +  and keeled +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
parallel +  and divergent +
terete +, rolled +  and plicate +
50 cm500 mm <br />0.5 m <br /> (85 cm850 mm <br />0.85 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
20 cm200 mm <br />0.2 m <br /> (50 cm500 mm <br />0.5 m <br />) +
scabridulous +
trigonous +
1mm;2mm +
ascending +  and spreading +
Ala. +, Ark. +, Del. +, D.C. +, Fla. +, Ga. +, La. +, Md. +, Miss. +, Mo. +, N.J. +, N.Y. +, N.C. +, Okla. +, S.C. +, Tenn. +, Tex. +, Va. +  and Mexico (Tamaulipas) +
0–1000 m +
laterally greenish +  and yellowish white +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
oblong +  and oblong-lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
Open woods and thickets in moist to dry, sandy soils +
subumbellate +  and capitate +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
40 cm400 mm <br />0.4 m <br /> (55 cm550 mm <br />0.55 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
10 cm100 mm <br />0.1 m <br /> (?) +  and 40 cm400 mm <br />0.4 m <br /> (?) +
w--shaped +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
30 cm300 mm <br />0.3 m <br /> (55 cm550 mm <br />0.55 m <br />) +
14 cm140 mm <br />0.14 m <br /> (30 cm300 mm <br />0.3 m <br />) +
scabridulous +
flat;broadly v-shaped +
1mm +  and 5mm +
with (1-)3-6(-30) bristles and/or scales +
Fruiting summer (Jun–Aug). +
2-3(-4)-carpellate +
antrorse +  and extrorse +
3 (?) +  and 1 (?) +
continuous +, articulate +, winged +  and wingless +
conspicuous +
3.5 cm35 mm <br />0.035 m <br /> (8.5 cm85 mm <br />0.085 m <br />) +
unequal +
4 +  and 8 +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
W2 +, W1 +  and Illustrated +
1.2 cm12 mm <br />0.012 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
oblong-ovoid +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
40 +  and 120 +
subterete;oblong-lanceoloid +
0.8mm;1.6mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
2-3-fid +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
papillose +
Mariscus retrorsus +
Cyperus retrorsus +
Cyperus subg. Cyperus +
species +
herb +  and cespitose +
persistent +
0.2mm +  and 0.3mm +