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

fuzzy flatsedge

sand flatsedge, Schweinitz's flatsedge

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

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

trigonous, (10–)20–50 cm × (0.6–)1–2 mm, glabrous or more often scabridulous, either in distal 1/2 or over entire length;

basal sheaths, 1–3, light brown, 1–4 cm, papery.

Leaves

flat, 10–35 cm × 3–10 mm.

flat to V-shaped, (2–)20–35 cm × 2–6 mm, margins and keel minutely scabridulous;

proximal leaves bladeless.

Inflorescences

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.

spikes ± umbellate to slenderly (infrequently broadly) ovoid, 10–25 × 7–16 mm;

rays 3–5, 1.5–8(–15) cm;

bracts 3–7, erect (or declined at most 25–30° from vertical), (2.5–)8–20(–25) cm × (0.5–)1.5–6 mm;

rachilla ± deciduous, wingless.

Spikelets

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.

(1–)5–10(–20), oblong to linear-oblong, quadrangular, 7–10(–18) × (2.8–)3.2–4(–4.5) mm;

floral scales deciduous, (1–)5–10(–14), spreading, laterally stramineous or dull whitish, sometimes also red-spotted, medially green, laterally 2–3-ribbed, medially 3-ribbed, broadly ovate to oblong-ovate, (2.3–)2.8–3.2 × (2–)2.4–3.2 mm, apex broadly rounded, often clear-erose, cusp 0.1–0.4 mm in proximal scales, 0.3–1 mm in distal scales.

Flowers

anthers 0.4 mm;

styles 0.6 mm;

stigmas 1 mm.

anthers 0.8–1.4 mm;

styles 0.1–0.3 mm;

stigmas 1.5–3 mm.

Achenes

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

light to dark brown or nearly black, broadly ellipsoid, infrequently obovoid, 2–2.4 × 0.9–1.4 mm, base cuneate to ± stipelike, apex obtuse to broadly rounded, surfaces papillose.

2n

= 166.

Cyperus pilosus

Cyperus schweinitzii

Phenology Fruiting summer. Fruiting late spring–early summer.
Habitat Rice fields, wetlands, emergent muddy shores Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods
Elevation 0–50 m (0–200 ft) 0–1000 m (0–3300 ft)
Distribution
from FNA
FL; LA; MS; SC; Asia [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; IA; IL; KY; MA; MI; MN; MO; MT; NJ; NM; NY; OH; OK; PA; SD; TX; UT; WA; WI; WY; AB; MB; ON; QC; SK; Mexico (Coahuila)
[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.)

Cyperus schweinitzii is introduced, but not naturalized, in Massachusetts and Washington.

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

Source FNA vol. 23, p. 166. FNA vol. 23, p. 174.
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. 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
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. 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. alterniflorus
Name authority Vahl: Enum. Pl. 2: 354. (1805) Torrey: Ann. Lyceum Nat. Hist. New York 3: 276. (1836)
Web links