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mosquito flatsedge

pine flatsedge, pinewoods sedge

Habit Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. Herbs, perennial, rhizomatous, tending to form small clumps by basal offshoots.
Culms

stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous.

triquetrous, bulbous, thickened, (20–)30–80(–90) cm × 0.7–1.2 mm, glabrous proximally, becoming trigonous strongly scabridulous on distal angles, clothed with persistent reddish fibers at base.

Leaves

V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid.

flat to V-shaped, 20–45 cm × 2–4 mm.

Inflorescences

spikes appressed-ascending, narrowly cylindric, (2–)3–45 mm × (4–)7–10 mm;

rays (5–)9–12, 2–22(–30) cm; 2d order rays distinctly flattened, 1–10 cm; 3d order rays flattened, 0.5–3 cm;

rachis 2.5–4 cm;

bracts (6–)9–10, ascending at 45–75°, V- or inversely W-shaped, (5–)15–90 cm × 0.5–20 mm;

rachilla persistent, wings 0.2–0.4 mm wide.

spike 1, loosely ovoid to ovoid-ellipsoid, (1.5–)2.5–7 × (1–)1.5–3.5 cm;

rays (1–)2–4, to 6 cm; 2d order rays rarely present, to 2 cm; 3d order rays absent;

bracts (2–) 3, ± horizontal, 1–15(–21) cm × 0.4–3.5 mm;

rachilla deciduous, wings hyaline, 0.3–0.4 mm wide.

Spikelets

(4–)10–35, appressed-ascending, compressed, linear, 7–12(–15) × 0.6–1.2 mm;

floral scales deciduous, 6–20, marginally clear, laterally brown, medially green, laterally 2–3-ribbed, medially 1-ribbed, oblong-ovate, (3.2–) 3.8–4.3 × 1.2–1.7 mm, apex spreading, acute to obtuse, mucronulate.

(3–)8–26, reddish to reddish brown, linear, compressed-quadrangular, 8–18 × (2.4–)2.8–4 mm;

floral scales deciduous, 6–16, laterally reddish, medially green, occasionally red-glandular, laterally strongly 3(–4)-ribbed, medially punctate, 1–3-ribbed, ovate-lanceolate, (2.6–)2.8–3.3 × (1.4–)1.6–1.8(–2) mm, apex weakly 3-dentate, mucronulate, with tuft of crystalline prickles, medially glabrous.

Flowers

anthers 0.7–0.9 mm, connective apex bright red, oblong, to 0.1 mm;

styles 0.8–1.3 mm;

stigmas 2–3.3 mm.

anthers 0.8–1.1 mm;

styles 1–1.4 mm;

stigmas 1–1.4 mm.

Achenes

brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate.

brownish, stipitate, ellipsoid, 1.6–2 × (0.7–)0.9–1 mm, base whitish, stipe to 0.1–0.2 mm, apex obtuse, slightly apiculate, surfaces papillose.

Cyperus prolixus

Cyperus hypopitys

Phenology Fruiting summer. Fruiting late summer–early fall.
Habitat Coastal marshes Canyons in pine forests
Elevation 0–10 m [0–30 ft] 500–1500 m [1600–4900 ft]
Distribution
from FNA
LA; Mexico; Central America; South America
[BONAP county map]
from FNA
AZ; Mexico (Chihuahua, Durango, Sinaloa, Sonora)
[BONAP county map]
Discussion

Cyperus prolixus produces large plants, similar in habit to C. giganteus and C. papyrus but easily distinguished by flattened rays.

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

Of conservation concern.

Cyperus hypopitys can be recognized by the combination of reddish floral scales and sharp-angled culms.

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

Source FNA vol. 23, p. 167. FNA vol. 23, p. 178.
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. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, 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. 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
Synonyms C. amplissimus
Name authority Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) G. C. Tucker: Syst. Bot. Monogr. 43: 129, fig. 54. (1994)
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