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green flatsedge

pine barren flatsedge

Habit Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. Herbs, perennial, cespitose, shortly rhizomatous.
Culms

trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles.

trigonous, 20–50(–85) cm × 1–2(–4) mm, glabrous.

Leaves

4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm.

3–6(–10), 10–40(–55) cm × 1.5–4(–5) mm, V- to inversely W-shaped.

Inflorescence(s)

heads digitate to hemispheric, 1–3.5 cm diam.;

rays 6–12, 1–9(–14) cm; 2d order rays often present, (0.5–)1–3 cm; 3d order rays occasionally present, 5–12 mm;

bracts 4–8, horizontal to ascending at 30°, with prominent cross ribs,V-shaped, (1.5–)3–50(–75) cm × 0.5–13 mm; 2d order bracts 3–10 × 1–2 mm.

spike 1, densely oblong-ovoid often with small basal branches, 8–16 × 4–12(–16) mm;

rays 4–8(–11), 0.5–3.5(–8.5) cm;

bracts (3–)4–6(–10), ascending at (30–)45°, flat to broadly V-shaped, (4–)14–30(–55) cm × 1–5 mm, scabridulous along margins only;

rachilla deciduous, wings persistent, 0.2–0.3 mm wide.

Spikelets

10–40(–50), oblong to linear-lanceoloid, 5–18 × 2–3.2 mm;

floral scales 10–40, pale grayish brown, or greenish, proximally greenish or brownish, oblanceolate, 2-keeled, weakly to distinctly 1-ribbed, proximal half 2-ribbed, (1.3–)1.5–2(–2.4) × 0.9–1.4 mm, apex acute (sometimes mucronulate), apically glabrous, occasionally scabridulous.

40–120, oblong-lanceoloid, subterete, 2.2–4(–4.5) × 0.8–1.6 mm;

distal spikelet spreading or ascending;

floral scales persistent, 2–5, appressed, brown to stramineous, or fuscous and lustrous, medially greenish and 1(–3)-ribbed, laterally greenish to yellowish white and 3–4-ribbed, oblong to oblong-lanceolate, 1.8–2.5 × 1–1.5 mm, subcoriacous.

Flowers

stamens 1–2;

anthers 0.8–1.4 mm;

styles 0.8–1 mm;

stigmas 0.6–0.8 mm.

anthers 0.3–0.5 mm;

styles 0.5–0.8 mm;

stigmas 0.6–0.9 mm.

Achenes

brown, slightly to distinctly stipitate, ellipsoid (2.7–4.1 times as long as wide), (0.9–)1.2–1.5 × 0.3–0.4 mm, apical beak 0.1–0.5 mm, surfaces glabrous.

brown, oblong-ellipsoid, 1.2–1.7 × 0.5–0.6 mm, base cuneate, apex subacute, surfaces papillose.

Cyperus virens

Cyperus retrorsus

Phenology Fruiting spring–fall. Fruiting summer (Jun–Aug).
Habitat Wet pastures, marshes, roadside ditches Open woods and thickets in moist to dry, sandy soils
Elevation 0–1000 m (0–3300 ft)
Distribution
from FNA
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; DC; DE; FL; GA; LA; MD; MO; MS; NC; NJ; NY; OK; SC; TN; TX; VA; Mexico (Tamaulipas)
[WildflowerSearch map]
[BONAP county map]
Discussion

Cyperus virens was found as waif in California in the 1800s (M. F. Denton 1978b; G. C. Tucker 1993b).

Cyperus virens is readily distinguished from other species of subg. Pycnostachys by its trigonous culms, scabrid angles, and leaves and inflorescence bracts conspicuously septate by numerous cross ribs between the main ribs.

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

Cyperus retrorsus was reported in Indiana (M. L. Horvat 1941); we have been unable to confirm the report.

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

Source FNA vol. 23, p. 153. FNA vol. 23, p. 187.
Parent taxa Cyperaceae > Cyperus > subg. Pycnostachys 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. 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. 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. 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 Mariscus cylindricus, C. cylindricus, Mariscus retrorsus
Name authority Michaux: Fl. Bor.-Amer. 1: 28. (1803) Chapman: Bot. Gaz. 3: 17. (1878)
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