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globe flatsedge, teasel sedge

buttonbush flatsedge

Habit Herbs, perennial, single-stemmed to loosely cespitose. Herbs, perennial, rhizomatous.
Culms

basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous.

trigonous, 40–70(–100) cm × 2–3 mm, scabrid or hirtellate, either immediately proximal to apex or over distal 1/2 of culm.

Leaves

flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous.

flat, 30–80 cm × 4–10 mm, scabrid on margins, ribs on abaxial surface.

Inflorescences

spikes densely globose to globose-ovoid, 8–17 mm wide;

rays 3–12, 2–12 cm, scaberous adaxially especially distally;

rachis 4–8 mm;

bracts (3–)4–7, ascending at 30(–45)°, flat, 5–35 cm × 2–9 mm;

rachilla persistent, wings 0.5–0.7 mm wide.

spikes ovoid, 12–20 × 13–18 mm;

rays 3–6, 4–10(–16) cm, glabrous;

bracts 3–5, ± horizontal to reflexed, 3–12(–36) cm × 0.4–3(–5) mm, scabrid like leaves;

rachilla deciduous, essentially wingless or wings inconspicuous, hyaline, 0.1(–0.2) mm wide.

Spikelets

50–100, oblong-lanceoloid, ± terete-quadrangular, (3.5–)4–7 × 1–1.4 mm;

distal spikelet spreading or ascending;

floral scales persistent, 3–5, appressed, stramineous to brownish, 4-ribbed laterally, oblong-elliptic, 3.5–4.5 × 1–1.8 mm, membranous, apex entire or emarginate with mucro to 0.3 mm.

25–50(–80), oblong, quadrangular-compressed, 5–10 × 2.5–3.5 mm;

floral scales deciduous, 4–10(–14), marginally clear, laterally brownish to clear distally, or light brown or reddish brown, blunt, laterally 3(–4)-ribbed, ovate-lanceolate, 2.5–3 × (1.2–)1.4–2 mm, often erose apically, apex acute to obtuse, entire or emarginate.

Flowers

anthers 0.4–0.8 mm;

styles 0.5–0.6 mm;

stigmas 1 mm.

anthers 0.4–0.6 mm;

styles 0.8–1.2 mm;

stigmas 2 mm.

Achenes

brown, ± stipitate, oblong, (1.5–)1.8–2.3 × 0.5–0.6(–0.7) mm (1/2 length of floral scales), apex obtuse, surfaces puncticulate.

brown to reddish brown, ± stipitate, ellipsoid, 1.2 × 0.5–0.6 mm, apex obtuse, scarcely to distinctly apiculate, surfaces puncticulate.

Cyperus echinatus

Cyperus cephalanthus

Phenology Fruiting summer–early fall. Fruiting summer.
Habitat Disturbed, sunny sites, in mesic places, well-drained soils Wet prairies
Elevation 0–500 m (0–1600 ft) 0–50 m (0–200 ft)
Distribution
from FNA
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; West Indies
[WildflowerSearch map]
[BONAP county map]
from FNA
LA; OK; TX; South America (Argentina, Brazil, Paraguay, Uruguay)
[BONAP county map]
Discussion

The records for Rhode Island and Wisconsin are according to M. L. Horvat (1941); we have not seen specimens from those states.

Cyperus echinatus is usually recognized by its tight, nearly spheric spikes; it may occasionally be hard to distinguish from C. croceus and C. retrorsus. Compared to C. retrorsus, C. echinatus has larger spikelets and longer floral scales, anthers, and achenes. In contrast to C. echinatus, C. croceus has looser spikes, shorter, broader, greenish or yellowish floral scales, shorter, more ovoid achenes, and shorter anthers. Furthermore, C. echinatus is predominantly an inland species of roadsides, pastures, and other disturbed ground; C. retrorsus is primarily a coastal species and occurs in drier, sandier sites.

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

The combination of spreading floral scales and scabrid culms separates this rather uncommon species from any others occurring in its range. The scarcity of Cyperus cephalanthus in the United States and its disjunct distribution suggest it might be naturalized rather than native. It was collected early in the nineteenth century in Louisiana, and the amphitropical distribution is not without parallel in the genus (cf. 12. C. eragrostis).

Cyperus cephalanthus has been treated as a variety of the widespread, polymorphic South American C. laetus (G. Kükenthal 1935–1936). Recognition of C. cephalanthus as a species follows recent American floristic practice.

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

Source FNA vol. 23, p. 182. FNA vol. 23.
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. 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. 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. virens
Synonyms Scirpus echinatus, C. ovularis, C. ovularis var. americanus, C. ovularis var. sphaericus, C. ovularis var. wolfii, C. wolfii, Kyllinga ovularis, Mariscus ovularis C. laetus var. cephalanthus
Name authority (Linnaeus) Alph. Wood: Class-book Bot. ed. s.n.(b), 734. (1861) Torrey & Hooker: Ann. Lyceum Nat. Hist. New York. 3: 431. (1836)
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