The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

umbrella flat sedge

fuzzy flatsedge

Habit Herbs, annual, cespitose, with fibrous roots. Herbs, annual or perennial, cespitose; stolons slender, to 5 cm × 1.5 mm.
Culms

trigonous, 4–25(–35) cm, glabrous.

trigonous, 25–90 cm × 2 mm, hispidulous or glabrous on angles distally.

Leaves

flat, 5–20 cm × 1.5–3 mm.

flat, 10–35 cm × 3–10 mm.

Inflorescences

heads ± digitate, 12–22 mm diam.;

rays 3–6, 1–6 cm;

bracts 1–4, ± horizontal, flat, 1.5–15 cm × 1.5–3 mm.

spikes 1–4(–6), loosely oblong-ovoid, 2–3 × 1–2 cm;

rays 3–10, 1–16 cm; 2d order rays to 3 cm;

rachis hispidulous, prickles slender, 0.1–0.2 mm;

bracts 3–5, ± ascending, flat, 5–35 cm × 0.5–5(–7) mm;

rachilla persistent, wingless.

Spikelets

6–12, oblong-lanceoloid, compressed, 5–10 × 2.8–3.2 mm;

floral scales 8–28, closely imbricate, stramineous to light brown or clear (marginal band bright red, spikelet thus appearing dark margined), laterally ribless, oblong to ovate, 2.5–3 × 1.6–1.9 mm.

15–40, linear-lanceoloid, compressed, 6–12 × 1.5–2 mm;

floral scales deciduous, 8–16, light brown with clear border, laterally 2–3-ribbed, ovate, 1.8–2 × 1.2–1.6 mm;

apex entire, emarginate, or mucronulate, mucro at most 0.3 mm.

Flowers

stamens 2(–3);

anthers 0.3 mm, connective apex reddish, subulate, 0.1–0.2 mm;

styles 0.3–0.5 mm;

stigmas 2.2–3.1 mm.

anthers 0.4 mm;

styles 0.6 mm;

stigmas 1 mm.

Achenes

brown, network of ridges forming isodiametric or square cells, sessile or stipitate, obovoid to ovoid, 1–1.2 × 0.5–0.6 mm, stipe, if present, 0.1 mm, apex obtuse, apiculate, surfaces minutely punctate.

brown, sessile, broadly ellipsoid, 1–1.2 × 0.5 mm, apex obtuse, apiculate, surfaces puncticulate.

Cyperus diandrus

Cyperus pilosus

Phenology Fruiting summer. Fruiting summer.
Habitat Emergent shorelines, in sandy, peaty, or slightly brackish areas (though seldom where disturbed) Rice fields, wetlands, emergent muddy shores
Elevation 0–600 m (0–2000 ft) 0–50 m (0–200 ft)
Distribution
from FNA
CT; DE; IA; IL; IN; MA; MD; ME; MI; MN; MO; NE; NH; NJ; NY; PA; RI; VA; VT; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; LA; MS; SC; Asia [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
Discussion

Cyperus pilosus was naturalized in the flora from eastern Asia, apparently early in the twentieth century.

The combination of hispidulous rachis and loosely oblong-ovoid spikes is sufficient to distinguish Cyperus pilosus from any others with deciduous floral scales.

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

Source FNA vol. 23, p. 161. FNA vol. 23, p. 166.
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. 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. 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. 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 Pycreus diander
Name authority Torrey: Cat. Pl. New York, 90. (1819) Vahl: Enum. Pl. 2: 354. (1805)
Web links