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umbrella-plant

hermaphrodite flatsedge

Habit Herbs, perennial, cespitose, rhizomatous. Herbs, perennial, rhizomatous.
Culms

trigonous, 30–150 cm × 1–5(–8) mm.

trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous.

Leaves

bladeless.

V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous.

Inflorescences

heads digitate, 15–30(–36) mm diam.;

rays (14–)20–22, (2–)5–12(–20) cm; 2d order rays 0.3–3(–4) cm; 3d order rays sometimes present, 0.3–2.5 cm;

bracts (4–)18–22, ± horizontal, flat, 15–27 cm × (1.5–)8–12 mm.

spikes 1(–5), rather densely ovoid or oblong-cylindric, (10–)25–45(–62) × 7–22 mm, 11–21 spikelets per 5 mm of rachis;

rays (3–)5–10(–17), (1–)5–12(–24) cm;

bracts (2–)4–8, ascending at 30–45°, V- or inversely W-shaped, (2–)8–40(–65) cm × (1–)2–8 mm;

rachilla deciduous, wings 0.4–0.5 mm wide.

Spikelets

8–20, ovoid to linear-lanceoloid, compressed, 5–25 × 1.5–2 mm;

floral scales 8–28, laterally whitish or light brown, ± hyaline, medially light brown, laterally ribless, medially 3-ribbed, 2-keeled in proximal 30–60%, deltate-ovate, 1.6–2.4 × (1–)1.2–1.5(–1.7) mm, apex acute.

(10–)50–150, oblong to linear, quadrangular, (3–)4–8(–18) × (0.8–)1–1.2(–1.6) mm;

distal spikelet spreading or ascending;

floral scales (1–) 3–8, pale greenish white to golden brown, deep brown, or reddish brown, medially usually green, weakly to strongly 3(–4)-ribbed laterally, 1–3-ribbed medially, ovate to elliptic, (2–)2.6–3.2(–4) × 1.2–2 mm, apex obtuse.

Flowers

stamens 3;

anthers 0.7–1 mm;

styles 0.5–1 mm;

stigmas 0.6–1 mm.

anthers (0.4–)0.6–1 mm;

styles 0.4–1.6 mm;

stigmas 1–1.5 mm.

Achenes

brown, sessile or stipitate, broadly ellipsoid, 0.6–0.8 × 0.4–0.6 mm, stipe if present to 0.1 mm, apex obtuse, apiculate, surfaces puncticulate.

brown or reddish brown, sessile or nearly so, ellipsoid, 1.4–1.8(–2) × 0.6–0.8(–1) mm, apex acute to obtuse, slightly apiculate, surfaces puncticulate.

Cyperus involucratus

Cyperus hermaphroditus

Phenology Fruiting early summer–fall. Fruiting summer–fall.
Habitat Damp, disturbed soils, ditches, stream banks Arroyos
Elevation 0–100(–800) m [0–300(–2600) ft] 500–1200 m [1600–3900 ft]
Distribution
from FNA
CA; FL; LA; TX; e Africa [Introduced in North America]
[BONAP county map]
from FNA
AZ; TX; Mexico; South America; West Indies
[BONAP county map]
Discussion

Cyperus involucratus has been collected in New York (R. S. Mitchell and G. C. Tucker 1997).

Cyperus involucratus is widely cultivated as a water plant in greenhouses and outdoors in warm-temperate or tropical climates. It has long been misidentified in the flora as C. alternifolius Linnaeus, an endemic of Madagascar (G. C. Tucker 1983).

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

An erroneous report of Cyperus hermaphroditus from Alabama was based on misidentification of C. thyrsiflorus.

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

Source FNA vol. 23, p. 150. Treatment authors: Gordon C. Tucker*, Brian G. Marcks*, J. Richard Carter *. FNA vol. 23, p. 186. Treatment authors: Gordon C. Tucker*, Brian G. Marcks*, J. Richard Carter *.
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. 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. 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
Synonyms Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii
Name authority Rottbøll: Descr. Pl. Rar., 22. (1772) (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916)
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