Cyperus odoratus


Sp. Pl. 1: 46. 1753.

Common names: Rusty flatsedge
Synonyms: Cyperus acicularis (Nees) Steudel Cyperus californicus S. Watson Cyperus eggersii Boeckeler Cyperus engelmannii Steudel Cyperus ferax Richard Cyperus ferax subsp. engelmannii (Steudel) Kükenthal Cyperus ferax subsp. speciosus (Vahl) Kükenthal Cyperus ferruginescens (Kunth) M. C. Johnston Cyperus haenkei Liebmann Cyperus huarmensis Schultes Cyperus macrocephalus Britton Cyperus michauxianus Vahl Cyperus odoratus var. engelmannii (Steudel) J. Rich. Carter, S. D. Jones & Wipff Cyperus oxycarioides Schrader ex Nees Cyperus speciosus (Linnaeus) Schrader ex Nees Cyperus squarrosus var. parvus Britton Diclidium aciculare Kunth Diclidium odoratum (Boeckeler) C. B. Clarke Mariscus ferax (Richard) Urban Mariscus huarmensis (Liebmann) T. Koyama Torulinium eggersii (Schultes) C. B. Clarke Torulinium ferax (Linnaeus) S. S. Hooper Torulinium macrocephalum Torulinium michauxianum Torulinium odoratum
Treatment appears in FNA Volume 23. Treatment on page 191. Mentioned on page 145, 146, 184, 188.

Herbs, annual (or short-lived perennial). Culms trigonous, (4–)10–50(–130) cm × (0.5–)1–4 mm. Leaves flanged V- or inversely W-shaped, 5–30(–60) cm × 4–12 mm. Inflorescences: spikes 1–5(–12), loosely to densely cylindric, ovoid, or ± pyramidal, 10–20(–40) × (8–)10–30(–35) mm; rays (0–2)6–9(–12), 2–8(–13) cm; if rays absent, infloresence a single dense, capitate cluster of closely imbricate spikes; bracts (4–)5–8(–10), horizontal to ascending at 30–60°, (3–)10–25(–55) cm × 1–14 mm; rachilla hyaline or thickened bronze, carmine, or yellowish, wings clasping achene. Spikelets (10–)20–60(–100), linear-oblong to narrowly linear, cylindric to slightly flattened (when scale tips spreading), (5–)8–15(–38) × 0.8–1.3(–1.9) mm; floral scales (4–)8–12–(30), medially green, laterally reddish to stramineous to shiny brown or beige, medially 2–5-ribbed, laterally 1–3-ribbed, ovate to elliptic, (2–)2.2–2.8(–3.2) × (1.2–)1.4–1.6(–1.8) mm, apex entire or emarginate with mucro to 0.3 mm. Flowers: anthers (0.2–)0.3–0.4(–0.7) mm; styles 0.4–0.7(–1) mm; stigmas (1–)1.5–3 mm. Achenes brown, reddish brown, or black, stipitate, narrowly ellipsoid to oblong (rarely obovoid-oblong), (1–)1.2–1.5(–1.9) × 0.5–0.6(–0.75) mm, stipe 0.1–0.2 mm, apex acute to barely obtuse, surfaces finely papillose.

Phenology: Fruiting summer–early fall.
Habitat: Emergent shorelines, disturbed, muddy places, fresh or slightly brackish marshes
Elevation: 0–1500 m


V23 331-distribution-map.jpg

Ont., Que., Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., Wash., W.Va., Wis., Central America, South America, Asia, Africa, Pacific Islands (Hawaii), Australia.


As circumscribed here, Cyperus odoratus is easily identified by its cylindric to subcylindric spikelets in which the corky rachilla of the mature spikelet disarticulates at the base of each scale. The mature spikelet breaks into segments each consisting of a scale and an internode of the rachilla clasping the achene with its corky wings. Cyperus odoratus is an exceedingly variable pantropical and warm-temperate species. Numerous segregates have been named, some of which may deserve recognition when the species is studied in detail worldwide.

Selected References


Lower Taxa

... more about "Cyperus odoratus"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Linnaeus +
Undefined subg. Diclidium +
Rusty flatsedge +
Ont. +, Que. +, Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +, Central America +, South America +, Asia +, Africa +, Pacific Islands (Hawaii) +  and Australia. +
0–1500 m +
Emergent shorelines, disturbed, muddy places, fresh or slightly brackish marshes +
Fruiting summer–early fall. +
W2 +, W1 +  and Illustrated +
Cyperus acicularis +, Cyperus californicus +, Cyperus eggersii +, Cyperus engelmannii +, Cyperus ferax +, Cyperus ferax subsp. engelmannii +, Cyperus ferax subsp. speciosus +, Cyperus ferruginescens +, Cyperus haenkei +, Cyperus huarmensis +, Cyperus macrocephalus +, Cyperus michauxianus +, Cyperus odoratus var. engelmannii +, Cyperus oxycarioides +, Cyperus speciosus +, Cyperus squarrosus var. parvus +, Diclidium aciculare +, Diclidium odoratum +, Mariscus ferax +, Mariscus huarmensis +, Torulinium eggersii +, Torulinium ferax +, Torulinium macrocephalum +, Torulinium michauxianum +  and Torulinium odoratum +
Cyperus odoratus +
Cyperus subg. Diclidium +
species +