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pale umbrella-sedge, sharp-point flatsedge, short flatsedge, short point cyperus, taper-tip cyperus, taper-tip flat sedge

plains flatsedge

Habit Herbs, annual, cespitose. Herbs, perennial, cespitose, rhizomatous; base cormlike; rhizomes scaly, 12 cm × 2 mm.
Culms

roundly trigonous, (10–)20–30(–45) cm × 0.4–1.2 mm, distal 1/2 glabrous or infrequently scabridulous.

trigonous, 20–55 cm × 1.2–11.8 mm, glabrous.

Leaves

2–6(–8), V-shaped or flat, 8–12(–16) cm × 1–2(–4) mm.

V-shaped, 12–30 cm × 2–3 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.

heads digitate, 12–20 mm diam.;

rays 7–12, 1–13 cm; 2d order rays 1–3 cm (sometimes absent);

bracts 3–5, longest ± erect, V-shaped, 5–12(–18) cm × 2–3 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.

(8–)20–30, linear-lanceoloid, compressed, 5–10(–14) × 1.4–1.7 mm;

floral scales (8–)16–26, laterally brown to reddish brown, medially green, laterally 1-ribbed, medially 3-ribbed, broadly elliptic, 2–2.5 × 1.2–1.6 mm, apex with slightly excurved cusp 0.2–0.3 mm.

Flowers

stamen 1;

anthers 0.5 mm;

styles 0.8–1.1 mm;

stigmas 0.5 mm.

stamens 3;

anthers 1 mm, connective apex reddish, subulate, 0.1 mm;

styles 1–1.5 mm;

stigmas 1.5 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.

white to light brown, sessile, ellipsoid, 0.7–0.8 × 0.25–0.35 mm, apex obtuse, apiculate, surfaces puncticulate.

Cyperus acuminatus

Cyperus onerosus

Phenology Fruiting summer–fall (Jul–Oct). Fruiting early summer (May–Jun).
Habitat Wet, often sandy shores and damp, disturbed soils Permanent pools and wet swales between sand dunes
Elevation 0–1500 m (0–4900 ft) 1200 m (3900 ft)
Distribution
from USDA
Mexico (Coahuila, Tamaulipas) [Ala., Ariz., Ark., Calif., Colo., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Mo., Mont., Nebr., N.H., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa. (introduced?), S.Dak., Tenn., Tex., Utah, Va., Wash., Wyo.]
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Cyperus acuminatus may be introduced in New Hampshire and New York.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Of conservation concern.

Cyperus onerosus is apparently restricted to Andrews and Winkler counties in Texas.

This interesting endemic is most similar to Cyperus dentatus; it lacks tubers and apparently is not proliferous.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 152. FNA vol. 23, p. 151.
Parent taxa Cyperaceae > Cyperus > subg. Pycnostachys Cyperaceae > Cyperus > subg. Pycnostachys
Sibling taxa
C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
Synonyms C. acuminatus var. cyrtolepis, C. cyrtolepis, C. cyrtolepis var. denticarinatus, C. rufescens var. denticarinatus
Name authority Torrey & Hooker: Ann. Lyceum Nat. Hist. New York 3: 435. (1836) M. C. Johnston: SouthW. Naturalist 9: 308. (1964)
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