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sharpscale flatsedge

foxtail flatsedge

Habit Herbs, perennial, cespitose, coarse, (culms, leaves, bracts, and rays viscid). Herbs, perennial, rhizomatous, coarse.
Culms

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

trigonous, 150–250 cm × 2–15 mm, glabrous.

Leaves

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

inversely W-shaped, 30–150 cm × 6–22 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.

spikes 1–4, cylindric, 1.5–4 cm × 7–15 mm;

rays 3–9, 10–26 cm; 2d order rays 2–11 cm; 3d order rays 1–4 cm (or absent);

bracts 3–5, ± horizontal, 20–100 cm × 3–15 mm; 2d order bracts 2–7 cm × 2–7 mm; 3d order bracts 2–5 cm × 2–4 mm (or absent);

rachilla persistent, wingless or wing hyaline, narrow, 0.1 mm wide.

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.

50–100, linear, ± quadrangular, slightly compressed, 8–11 × 0.9–1.2 mm;

floral scales 15–30, marginally clear, laterally reddish along midrib, medially green, laterally 3–4 ribbed, medially 3–5-ribbed, ovate, 1–2–1.6 × 1.1–1.3 mm, apex mucronulate.

Flowers

anthers 0.6–0.8 mm;

styles 0.8–1.6 mm;

stigmas 1–1.4 mm.

anthers 2, 0.4–0.5 mm;

styles 0.8–1 mm;

stigmas 2, 0.4 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.

dark brown, sessile, ellipsoid to obovoid, 0.9 × 0.4–0.5 mm, surfaces finely puncticulate.

Cyperus oxylepis

Cyperus alopecuroides

Phenology Fruiting summer. Fruiting summer.
Habitat Ditches and disturbed places in marshes, often in saline soil Pond shores, stream banks
Elevation 0–100 m (0–300 ft) 0–30 m (0–100 ft)
Distribution
from FNA
AR; FL; GA; LA; MS; SC; TX; Mexico; South America [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; West Indies; Asia; Africa; Australia [Introduced in North America]
[BONAP county map]
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.)

Cyperus alopecuroides has been introduced in Polk County, Florida.

Plants of Cyperus alopecuroides might be confused with C. digitatus; large size and the biconvex achenes with two stigmas characterize C. alopecuroides.

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

Source FNA vol. 23, p. 171. FNA vol. 23, p. 173.
Parent taxa Cyperaceae > Cyperus > subg. Cyperus Cyperaceae > Cyperus > subg. Cyperus
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. 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
Name authority Nees ex Steudel: Syn. Pl. Glumac. 2: 25. (1855) Rottbøll: Descr. Pl. Rar., 20. (1772)
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