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sharpscale flatsedge

tooth flatsedge

Habit Herbs, perennial, cespitose, coarse, (culms, leaves, bracts, and rays viscid). Herbs, perennial, cespitose, rhizomatous; stolons tuberiferous, 1–10 cm.
Culms

roundly trigonous, 10–50 cm × 0.9–2.4 mm.

trigonous, 8–50 cm × 1–3 mm.

Leaves

adaxial face concave, becoming flat to trigonous apically, 10–46 cm × 1.5–4 mm, margins involute.

flat or V-shaped, 10–40 cm × 2–5 mm.

Inflorescences

spikes ovoid, 1–5.5 cm wide;

rays usually 3–6, 0.5–5 cm, glabrous;

sometimes absent in small plants;

if absent, inflorescence a congested head of spikelets 1–3.5 cm diam.; 2d order rays 0–3, 1–3 cm;

bracts 3–5, vertical to ascending at 45°, 2.5–25 cm × 1.2–4 mm, margins involute; 2d order bracts 0–2, 5–20 mm;

rachilla persistent, wingless.

heads digitate, 8–18 mm diam.;

rays 4–9, 1–8 cm; 2d order rays 0.5–2 cm;

bracts 3–5, ± horizontal, flat, 1–20 cm × 1–4 mm.

Spikelets

5–24, greenish yellow to golden brown, oblong to linear-lanceoloid, quadrangular, strongly compressed, 7–20(–30) × 2.5–4(–6) mm;

floral scales 10–20(–40), spreading, pale green to stramineous, laterally 2–3-ribbed, ovate-lanceolate, 3.1–4 × 1.5–2.4 mm, apex with mucro 0.2–0.8 mm.

commonly proliferous, 2–6, linear to oblong, compressed, 3–24 × 2–2.5 mm;

floral scales 3–20(–50), reddish brown, laterally 1–3-ribbed, ovate, 2–2.5 × 1.5–2 mm.

Flowers

anthers 0.6–0.8 mm;

styles 0.8–1.6 mm;

stigmas 1–1.4 mm.

stamens 3;

anthers 1.5 mm;

styles 1 mm;

stigmas 1.5 mm.

Achenes

light to dark brown, rarely somewhat reddish, stipitate, ellipsoid, 2–2.4 × 0.5–0.8 mm, base cuneate, stipe whitish, spongy, 0.2–0.3 × 0.2–0.4 mm, apex acute, persistent style forming beak 0.5–1.2 mm, surfaces glabrous or finely papillose.

reddish brown, sessile, obovoid, 0.8–1 × 0.4–0.5 mm, apex obtuse, scarcely apiculate, surfaces glabrous.

Cyperus oxylepis

Cyperus dentatus

Phenology Fruiting summer. Fruiting summer.
Habitat Ditches and disturbed places in marshes, often in saline soil Emergent sandy, peaty, or gravelly shorelines
Elevation 0–100 m (0–300 ft) 0–600 m (0–2000 ft)
Distribution
from FNA
AR; FL; GA; LA; MS; SC; TX; Mexico; South America [Introduced in North America]
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from FNA
CT; DC; DE; IN; MA; MD; ME; NC; NH; NY; PA; RI; SC; TN; VA; VT; NB; NS; ON; QC
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Discussion

Cyperus oxylepis is easily recognized by its sticky leaves, culms, and bracts (in living plants), involute leaves,and golden brown spikelets. The ovate-lanceolate floral scales and the ellipsoid, brownish achene with a persistent beak distinguish C. oxylepis from other species with deciduous floral scales.

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

The report of Cyperus dentatus from West Virginia (M. V. McGivney 1938) is erroneous; the cited specimen was from New Jersey (Gutenberg s.n. 1886, US) (M. Strong, pers. comm.).

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

Source FNA vol. 23, p. 171. FNA vol. 23, p. 151.
Parent taxa Cyperaceae > Cyperus > subg. Cyperus Cyperaceae > Cyperus > subg. Pycnostachys
Sibling taxa
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. onerosus, C. ovatus, C. owanii, 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. 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
Name authority Nees ex Steudel: Syn. Pl. Glumac. 2: 25. (1855) Torrey: Fl. N. Middle United States 1: 61. (1824)
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