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roadside flatsedge

Habit Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. Herbs, annual or perennial, cespitose.
Culms

trigonous, 15–48 cm × 0.4–1 mm, glabrous.

trigonous, 15–60 cm × 1–3 mm, glabrous.

Leaves

flat, 10–30 cm × 0.5–2 mm.

2–6, flat to V-shaped, 6–30(–40) cm × 2–4 mm.

Inflorescences

spikes rather densely ovoid, 1–3.5 cm;

rays 0 (sometimes 1–4), 1–6 cm;

rachis 1–4 mm;

bracts 3–4, horizontal to slightly reflexed, flat, 6–25 cm;

rachilla ± deciduous, wingless.

spikes broadly ellipsoid, 5–45 × 10–30(–45) mm;

rays (2–)5–9, (0.3–)3–10 cm;

rachis 4–17 mm;

bracts 5–6, horizontal to ascending, V-shaped, 1.5–30 cm × 0.5–4 mm;

rachilla persistent, wings hyaline, 0.4–0.5 mm wide.

Spikelets

25–60, compressed, oblong-lanceoloid, 5–12 × 2.2–3.5 mm;

floral scales deciduous, 5–15, yellowish to yellowish brown, laterally 4–5-ribbed, oblong-ovate, 2.6–3.6 × 1.4–2 mm, margins loosely spreading or clasping achene.

5–30, pale greenish white or stramineous, compressed, linear-lanceoloid, 7–35 × (1.2–)1.4–2 mm;

floral scales deciduous, 6–34, spreading or appressed, laterally greenish white, often reddish or brown speckled, medially green, laterally 3–5-ribbed, medially 3-ribbed, elliptic, (2.2–)3–4(–4.4) × (1.2–)1.8–2.2 mm, apex acute.

Flowers

anthers 0.8–1 mm;

styles 1 mm;

stigmas 1.5–2.5 mm.

anthers 0.6 mm;

styles 0.6–1.2 mm;

stigmas 1–1.4(–1.7) mm.

Achenes

dark grayish brown, sessile, narrowly oblong, 1.8–2.2 × 0.5–0.8 mm, apex obtuse, apiculate, surfaces puncticulate.

reddish brown to dark brown, stipitate, narrowly ellipsoid, 1.4–2 × 0.6–0.9 mm, apex apiculate, surfaces puncticulate.

Cyperus filiculmis

Cyperus sphacelatus

Phenology Fruiting summer. Fruiting summer.
Habitat Well-drained, open roadsides, fields, pine barrens, dunes Disturbed, wet soils
Elevation 0–200 m (0–700 ft) 0 m (0 ft)
Distribution
from FNA
AL; FL; GA; LA; MD; MS; NC; SC; TX; VA
from FNA
FL; Central America; South America; West Indies; Africa [Introduced in North America]
[BONAP county map]
Discussion

Cyperus filiculmis has long been treated within a broader and more widely used concept of C. filiculmis (C. lupulinus); see B. G. Marcks (1974)

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

Source FNA vol. 23, p. 175. FNA vol. 23, p. 170.
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. 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. 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. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
Synonyms C. martindalei C. balbisii
Name authority Vahl: Enum. Pl. 2: 328. (1805) Rottbøll: Descr. Pl. Rar., 21. (1772)
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