Cyperus polystachyos

Rottbøll

Descr. Pl. Rar., 21. 1772.

Illustrated
Synonyms: Cyperus brizaeus J. Presl & C. Presl Cyperus polystachyos var. leptostachyus Boeckeler Pycreus polystachyos
Treatment appears in FNA Volume 23. Treatment on page 160. Mentioned on page 142, 159, 184.

Herbs, perennial (annual?), cespitose. Culms trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous. Leaves (2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm. Inflorescences: spike 1, loosely ovoid to densely turbinate, 12–40 × 10–25 mm; rachis 3–10 mm; rays 1–8(–12), 0.5–3(–6) cm; 2d order rays absent; if rays absent, inflorescence single dense cluster of spikelets, 12–40 mm diam.; bracts (3–)4–6(–7), horizontal to ascending at 45°, flanged V-shaped, (2–)5–15(–23) cm × 1–4 mm. Spikelets (5–)15–30(–40), spreading to appressed-ascending, linear-lanceoloid to linear, compressed, 8–18(–40) × (1–)1.3–1.6(–2) mm; floral scales (8–)12–25(–66), laterally stramineous to light brown, medially green, laterally ribless, medially 3–5-ribbed, oblong, (1.5–)1.8–2.4 × (1–)1.2–1.4 mm, apex acute to ± acute, mucronate. Flowers: stamens 2; anthers (0.4–)0.5–0.8 mm, connective not prolonged; styles 0.6–1(–1.4) mm; stigmas (1–)1.4–2 mm. Achenes light to dark brown, oblong, (0.8–)0.9–1.1(–1.2) × 0.4–0.5(–0.6) mm, base cuneate to ± stipelike, apex truncate, apiculate, surfaces punctate to minutely punctate with raised cells.


Phenology: Fruiting summer–early fall.
Habitat: Shores, ditches, swales between dunes
Elevation: 0–200 m

Distribution

V23 252-distribution-map.jpg

Ala., Del., D.C., Fla., Ga., Ky., La., Maine, Md., Mass., Miss., N.J., N.Y., N.C., Okla., Pa., S.C., Tex., Va., W.Va., Mexico, Central America, South America, Asia, Africa.

Discussion

Cyperus polystachyos is polymorphic. Adequate understanding of the infraspecific variations of C. polystachyos requires a worldwide examination, which is beyond the scope of this study. The segregates, C. fugax and C. filicinus, are recognized here; they have been usually accepted by recent workers (e.g., M. L. Fernald 1950; H. A. Gleason and A. Cronquist 1991).

Selected References

None.

Lower Taxa

None.
... more about "Cyperus polystachyos"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Rottbøll +
Undefined subg. Pycreus +
Ala. +, Del. +, D.C. +, Fla. +, Ga. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Miss. +, N.J. +, N.Y. +, N.C. +, Okla. +, Pa. +, S.C. +, Tex. +, Va. +, W.Va. +, Mexico +, Central America +, South America +, Asia +  and Africa. +
0–200 m +
Shores, ditches, swales between dunes +
Fruiting summer–early fall. +
Descr. Pl. Rar., +
W2 +, W1 +  and Illustrated +
Cyperus brizaeus +, Cyperus polystachyos var. leptostachyus +  and Pycreus polystachyos +
Cyperus polystachyos +
Cyperus subg. Pycreus +
species +