Cyperus acuminatus

Torrey & Hooker
Ann. Lyceum Nat. Hist. New York 3: 435. 1836.
Illustrated
Synonyms: Cyperus acuminatus var. cyrtolepis (Torrey & Hooker) Kükenthal Cyperus cyrtolepis Torrey & Hooker Cyperus cyrtolepis var. denticarinatus (Britton) Britton Cyperus rufescens var. denticarinatus Britton
Treatment appears in FNA Volume 23. Treatment on page 152. Mentioned on page 143, 150, 165.

Herbs, annual, cespitose. Culms roundly trigonous, (10–)20–30(–45) cm × 0.4–1.2 mm, distal 1/2 glabrous or infrequently scabridulous. Leaves 2–6(–8), V-shaped or flat, 8–12(–16) cm × 1–2(–4) mm. Inflorescences: heads hemispheric, 7–12(–15) mm diam.; rays 1–3(–5), 0.5–2 cm; bracts 3–6, longest erect to ascending, flat to V-shaped, (1.5–)3–12(–25) cm × 1–2.5(–3.5) mm. Spikelets (15–)25–50(–75), ovoid, compressed, 4–7 × 2–3 mm; floral scales 8–20(–35), laterally yellowish, yellowish green, or light reddish brown, medially light brown or greenish brown, 2-keeled, subtly 1-ribbed, ovate-lanceolate, 1–2 × 1–1.4 mm, apex acute, mucronate, straight to excurved, glabrous or sparsely scabridulous. Flowers: stamen 1; anthers 0.5 mm; styles 0.8–1.1 mm; stigmas 0.5 mm. Achenes brown, stipitate, broadly ellipsoid, abruptly contracted to base, 0.8–1.1 × 0.3–0.4 mm, stipe 0.1 mm, apex acute, tapering to slender beak formed of persistent style base, surfaces papillose.


Phenology: Fruiting summer–fall (Jul–Oct).
Habitat: Wet, often sandy shores and damp, disturbed soils
Elevation: 0–1500 m

Distribution

V23 233-distribution-map.jpg

Ala., Ariz., Ark., Calif., Colo., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Mo., Mont., Nebr., N.H. (introduced?), N.Y. (introduced?), N.C., N.Dak., Ohio, Okla., Oreg., Pa. (introduced?), S.Dak., Tenn., Tex., Utah, Va., Wash., Wyo., Mexico (Coahuila, Tamaulipas).

Discussion

Selected References

None.

Lower Taxa

None.

... more about "Cyperus acuminatus"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Torrey & Hooker +
Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, N.H. (introduced?) +, N.Y. (introduced?) +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. (introduced?) +, S.Dak. +, Tenn. +, Tex. +, Utah +, Va. +, Wash. +, Wyo. +, Mexico (Coahuila +  and Tamaulipas). +
0–1500 m +
Wet, often sandy shores and damp, disturbed soils +
Fruiting summer–fall (Jul–Oct). +
Ann. Lyceum Nat. Hist. New York +
Illustrated +
Cyperus acuminatus var. cyrtolepis +, Cyperus cyrtolepis +, Cyperus cyrtolepis var. denticarinatus +  and Cyperus rufescens var. denticarinatus +
Cyperus acuminatus +
Cyperus subg. Pycnostachys +
species +