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epiphytic flatsedge

mosquito flatsedge

Habit Herbs, perennial, cespitose, rhizomatous. Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate.
Culms

trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous.

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

Leaves

1–3, 5–30 cm × 1–2 mm.

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

Inflorescences

spikes 1(–2), ovoid, 5–23 × 9–21 mm;

rays 2–3(–4), 0–15 mm;

if rays absent, head single, compact, sessile, (12–)15–20 mm diam.;

bracts 2–3, horizontal to vertical, 2–14 cm × 0.5–3.5 mm.

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.

Spikelets

1–6, oblong-lanceoloid, 5–26 × 2–3 mm;

floral scales 12–54, closely imbricate, laterally yellowish brown, medially pale brown, occasionally greenish, laterally 1-ribbed, medially 3-ribbed, distinctly 2-keeled basally, ovate, 1.8–2.6 × 1.4–1.7 mm, apex obtuse.

(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.

Flowers

stamens 2;

anthers 0.4–0.5 mm, connectives not prolonged;

styles 0.3–1 mm;

stigmas 0.6–0.8(–1) mm.

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.

Achenes

brown, network of ridges forming isodiametric or square cells, stipitate, obovoid to ellipsoid, 1.1–1.3 × (0.5–)0.6 mm, apex acute to broadly rounded, surfaces minutely punctate or finely papillose.

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

Cyperus lanceolatus

Cyperus prolixus

Phenology Fruiting summer. Fruiting summer.
Habitat Marshes Coastal marshes
Elevation 0–100 m (0–300 ft) 0–10 m (0–0 ft)
Distribution
from FNA
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
[WildflowerSearch map]
[BONAP county map]
from FNA
LA; Mexico; Central America; South America
[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.)

Source FNA vol. 23, p. 162. FNA vol. 23, p. 167.
Parent taxa Cyperaceae > Cyperus > subg. Pycreus 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. 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. 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
Synonyms C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus C. amplissimus
Name authority Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816)
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