Cyperus reflexus

Vahl

Enum. Pl. 2: 299. 1805.

Illustrated
Synonyms: Cyperus arenicola Steudel Cyperus fraternus Kunth Cyperus pseudovegetus var. arenicola (Steudel) Kükenthal Cyperus reflexus var. fraternus (Kunth) Kuntze
Treatment appears in FNA Volume 23. Mentioned on page 153.

Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. Culms roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. Leaves 1–6, 10–40 cm, glabrous or essentially so. Inflorescences: heads ovoid to pyramidal, 9–15 mm diam.; rays 0 or 3–6, 0.5–4 cm, glabrous; bracts 3–4, longest erect, appearing as continuation of culm, others horizontal to ascending, 4–17 cm × 1.5–4 mm. Spikelets 25–60, reddish with contrasting yellowish or greenish edges, oblong-lanceoloid, strongly compressed, 5–6 (–15) × 1.5–2.5 mm; floral scales 10–22, laterally reddish, medially yellowish green, 2-keeled, laterally strongly 1-ribbed on each side, proximally grooved, ovate-elliptic, 1.4–2.2 × 0.8–1.5 mm, apex acute, apically scabridulous (sometimes glabrous). Flowers: stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. Achenes reddish-brown, stipitate, ovoid-ellipsoid, 0.8–0.9 × 0.3–0.4 mm, stipe 0.1–0.2 mm, apex acute to acuminate, surfaces reticulate or subtly rugulose.


Phenology: Fruiting late spring–fall (May–Oct).
Habitat: Muddy soils or shallow waters
Elevation: 0–200 m

Distribution

V23 234-distribution-map.jpg

Fla., La., Okla., Tex., Mexico, Central America (Costa Rica)

Discussion

Cyperus reflexus is recognized by its reddish scales with contrasting greenish or yellow keels and by the laterally 1ribbed scales. The lateral rib is most often situated where the reddish and yellowish parts of the scale meet. Two varieties of C. reflexus, var. reflexus and var. fraternus, have been recognized (M. F. Denton 1978b). Both varieties were noted as intermingled in the North American and South American segments of the widely disjunct range of C. reflexus. Such variation does not seem significant at the varietal level (see G. C. Tucker 1994; G. C. Tucker and R. McVaugh 1993).

Selected References

None.

Lower Taxa

None.

"shortened" is not a number."longest" is not a number.

... more about "Cyperus reflexus"
reddish-brown +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
ovoid-ellipsoid +
0.3mm;0.4mm +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
scabridulous +
acute;acuminate +
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 +
parallel +  and divergent +
terete +, rolled +  and plicate +
30 cm300 mm <br />0.3 m <br /> (80 cm800 mm <br />0.8 m <br />) +
scabridulous +
roundly trigonous +  and terete +
1mm;1.6mm +
Fla. +, La. +, Okla. +, Tex. +, Mexico +  and Central America (Costa Rica) +
greenish +  and yellowish +
0–200 m +
yellowish green +  and reddish +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
ovate-elliptic +  and 2-keeled +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
hypogynous +  and subtending +
biconvex +  and trigonous +
Muddy soils or shallow waters +
digitate +, glomerulate +  and umbellate +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
ovoid +  and pyramidal +
subumbellate +  and capitate +
spreading +  and erect +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
essentially;glabrous +
10 cm100 mm <br />0.1 m <br /> (40 cm400 mm <br />0.4 m <br />) +
4 cm40 mm <br />0.04 m <br /> (17 cm170 mm <br />0.17 m <br />) +
horizontal;ascending +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
Fruiting late spring–fall (May–Oct). +
2-3(-4)-carpellate +
antrorse +  and extrorse +
3 (?) +  and 1 (?) +
unequal +
3 +  and 6 +
0.5 cm5 mm <br />0.005 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.3 cm3 mm <br />0.003 m <br /> (?) +
adventitious +
basal +  and proximal +
cylindric;compressed +
cylindric +
Illustrated +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
25 +  and 60 +
compressed;oblong-lanceoloid +
1.5mm;2.5mm +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (?) +  and 0.02 cm0.2 mm <br />2.0e-4 m <br /> (?) +
2-3-fid +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
rugulose +  and reticulate +
Cyperus arenicola +, Cyperus fraternus +, Cyperus pseudovegetus var. arenicola +  and Cyperus reflexus var. fraternus +
Cyperus reflexus +
Cyperus subg. Pycnostachys +
species +
tuberous +, stoloniferous +  and rhizomatous +
herb +  and cespitose +