Cyperaceae

A large and difficult family, with 16 genera and 272 species in Michigan. Identification of all but the most distinctive species usually requires mature fruit. The floral structure is simple, with usually bisexual flowers subtended by a single scale (not two, the lemma and palea, as in grasses), and then arranged into spikelets of varied morphology. An exception is Scleria, where flowers are unisexual. In Carex, the flowers are also unisexual, but the female are enclosed in a sac, flask, bottle, or tube-shaped, often flattened, structure called the perigynium, this then subtended by a single bract. See Rothrock (2009) for a fine illustrated treatment of the non-Carex genera, with a focus on Indiana.

1. Achenes enclosed in a closed sac (perigynium) subtended by a scale, the style protruding through the apex; flowers strictly unisexual (sedges with exclusively male flowers should be keyed here).

Carex

1. Achenes not enclosed in a closed sac, naked beside the subtending scale; at least some flowers bisexual (except in Scleria).

2. Achenes white, hard (bone-like), ± spherical; flowers all unisexual.

Scleria

2. Achenes yellow, brown, or black, rarely whitish, not spherical; at least some flowers bisexual.

3. Scales of spikelets 2-ranked; spikelets ± flattened in cross-section and always more than one per inflorescence.

4. Stems usually ± angled, solid; inflorescences terminal; achenes without subtending bristles.

Cyperus

4. Stems round, hollow; inflorescences in the axils of stem leaves; achenes with subtending bristles.

Dulichium

3. Scales of spikelets spirally arranged (or if 2-ranked, the spikelet solitary); spikelets round or several-angled in cross-section, solitary or several to many per inflorescence.

5. Perianth bristles 6, 3 slender and 3 with an expanded, ± spongy, spoon-like portion at the tip.

Fuirena

5. Perianth bristles absent or 1 to many, all slender.

6. Spikelet or cluster of spikelets borne on one side of the stem at the base of a single ± erect to somewhat angled or curved involucral bract that appears to be a continuation of the stem.

7. Stems less than 0.5 mm thick; plants tiny, less than 10 cm tall.

Lipocarpha

7. Stems thicker than 0.5 mm; plants usually much taller than 10 cm.

8. Plants colonial from elongate rhizomes, perennial; usually more than 0.8 m tall (except in the submerged aquatic Schoenoplectus subterminalis); anthers 1–3.5 mm long.

Schoenoplectus

8. Plants cespitose, annual, less than 0.8 (–1) m tall; anthers 0.3–0.9 mm long.

Schoenoplectiella

6. Spikelet or spikelets terminating the stem or borne both terminally and laterally; if more than one spikelet, the inflorescence with (1–) 2 to several spreading to reflexed, leaf-like involucral bracts.

9. Spikelet solitary and terminal on the stem (very rarely a few smaller accessory spikelets occur at the base of the terminal spikelet in the bladeless genus Eleocharis).

10. Sheaths totally bladeless or at most with an apical tooth up to 1 mm long; achenes usually with an apical tubercle formed by the expanded and persistent base of the style.

Eleocharis

10. Upper sheaths with short green blades 0.3–12 cm long; achenes blunt at apex, tubercle absent.

11. Achenes subtended by conspicuous silky, white or tawny, hair-like bristles many times as long as the achenes.

12. Bristles numerous, ca. (12–) 15–50 or more; rhizomes erect, very short.

Eriophorum (in part)

12. Bristles 6; rhizomes horizontal and short-creeping.

Trichophorum alpinum

11. Achenes subtended by 1–8 bristles less than twice as long as the achenes, or bristles absent.

Trichophorum (in part)

9. Spikelets several to many on the stem, terminal or lateral.

13. Achenes subtended by (12–) 15–50 conspicuous, silky, white or tawny, hair-like bristles many times as long as the achenes.

Eriophorum (in part)

13. Achenes subtended by 1–8 bristles, or bristles absent.

14. Leaves flat or folded; with a definite, ± keeled midrib.

15. Achenes with a conspicuous tubercle formed by the expanded, persistent style base.

Rhynchospora (in part)

15. Achenes blunt at apex, without a tubercle; style base, if expanded, not persistent to maturity.

16. Widest leaves 4–15 mm wide; achenes subtended by 1–8 bristles.

17. Spikelets (10–) 15–36 mm long; achenes 3–5 mm long, including apiculus; anthers ca. (2.3–) 4–5 mm long; culms sharply 3-angled nearly or quite to the base; colonial from rhizomes with large corm-like thickenings.

Bolboschoenus

17. Spikelets 2–10 (–12) mm long, achenes 0.9–1.2 mm long; anthers 0.5–1.3 mm long; culms terete, obtusely 3-angled, or sharply 3-angled only toward summit; cespitose or with rhizomes lacking corm-like enlargements.

Scirpus

16. Widest leaves 0.5–3 mm wide; achenes lacking bristles.

Fimbristylis

14. Leaves inrolled and wiry; rounded on the back and without a definite midrib.

18. Styles 2-cleft; achenes subtended by slender bristles.

Rhynchospora (in part)

18. Styles 3-cleft; achenes lacking bristles.

19. Achenes 2.2–3.5 mm long; perennials 4–11 dm tall; colonial from elongated rhizomes.

Cladium

19. Achenes 0.7–0.8 mm long; tufted annuals 0.2–4 dm tall.

Bulbostylis

All species found in Cyperaceae

Bolboschoenus fluviatilisBULRUSH
Bolboschoenus maritimusBULRUSH
Bulbostylis capillarisSEDGE
Carex acutiformisSEDGE
Carex adustaSEDGE
Carex aggregataSEDGE
Carex alataWINGED SEDGE
Carex albicansSEDGE
Carex albolutescensGREENISH-WHITE SEDGE
Carex albursinaSEDGE
Carex alopecoideaSEDGE
Carex amphibolaSEDGE
Carex annectensSEDGE
Carex aquatilisSEDGE
Carex arctaSEDGE
Carex arctataSEDGE
Carex argyranthaSEDGE
Carex assiniboinensisASSINIBOIA SEDGE
Carex atherodesSEDGE
Carex atlanticaSEDGE
Carex atratiformisSEDGE
Carex aureaSEDGE
Carex backiiSEDGE
Carex bebbiiSEDGE
Carex bicknelliiSEDGE
Carex billingsiiSEDGE
Carex blandaSEDGE
Carex breviorSEDGE
Carex bromoidesSEDGE
Carex brunnescensSEDGE
Carex bushiiBUSH'S SEDGE
Carex buxbaumiiSEDGE
Carex canescensSEDGE
Carex capillarisSEDGE
Carex careyanaSEDGE
Carex castaneaSEDGE
Carex cephaloideaSEDGE
Carex cephalophoraSEDGE
Carex chordorrhizaSEDGE
Carex communisSEDGE
Carex comosaSEDGE
Carex concinnaBEAUTY SEDGE
Carex conjunctaSEDGE
Carex conoideaBEAUTY SEDGE
Carex craweiSEDGE
Carex crawfordiiSEDGE
Carex crinitaSEDGE
Carex cristatellaSEDGE
Carex crus-corviSEDGE
Carex cryptolepisSEDGE
Carex cumulataSEDGE
Carex davisiiDAVIS' SEDGE
Carex debilisSWAMP SEDGE
Carex decompositaLOG SEDGE
Carex deflexaSEDGE
Carex deweyanaSEDGE
Carex diandraSEDGE
Carex digitalisSEDGE
Carex dispermaSEDGE
Carex duriusculaSEDGE
Carex eburneaSEDGE
Carex echinataSEDGE
Carex echinodesSEDGE
Carex emoryiSEDGE
Carex exilisSEDGE
Carex festucaceaFESCUE SEDGE
Carex flaccaSEDGE
Carex flavaSEDGE
Carex foeneaSEDGE
Carex folliculataSEDGE
Carex formosaSEDGE
Carex frankiiFRANK'S SEDGE
Carex garberiSEDGE
Carex gracilescensSEDGE
Carex gracillimaSEDGE
Carex granularisSEDGE
Carex gravidaSEDGE
Carex grayiSEDGE
Carex griseaSEDGE
Carex gynandraSEDGE
Carex gynocratesSEDGE
Carex haydeniiHAYDEN'S SEDGE
Carex heleonastesSEDGE
Carex hirsutellaSEDGE
Carex hirtaSEDGE
Carex hirtifoliaSEDGE
Carex hitchcockianaSEDGE
Carex houghtonianaSEDGE
Carex hyalinolepisSEDGE
Carex hystericinaSEDGE
Carex inopsSEDGE
Carex interiorSEDGE
Carex intumescensSEDGE
Carex jamesiiJAMES' SEDGE
Carex lacustrisSEDGE
Carex laevivaginataSEDGE
Carex lasiocarpaSEDGE
Carex laxiculmisSEDGE
Carex laxifloraSEDGE
Carex leavenworthiiSEDGE
Carex lenticularisSEDGE
Carex leptaleaSEDGE
Carex leptonerviaSEDGE
Carex limosaBOG SEDGE
Carex lividaSEDGE
Carex longiiSEDGE
Carex lucorumSEDGE
Carex lupuliformisSEDGE
Carex lupulinaSEDGE
Carex luridaSEDGE
Carex magellanicaSEDGE
Carex meadiiSEDGE
Carex mediaSEDGE
Carex merritt-fernaldiiSEDGE
Carex mesochoreaSEDGE
Carex michauxianaSEDGE
Carex molestaSEDGE
Carex muehlenbergiiSEDGE
Carex muricataSEDGE
Carex muskingumensisSEDGE
Carex nigraBLACK SEDGE
Carex normalisSEDGE
Carex novae-angliaeNEW ENGLAND SEDGE
Carex oligocarpaSEDGE
Carex oligospermaSEDGE
Carex ormostachyaSEDGE
Carex pallescensPALE SEDGE
Carex paucifloraSEDGE
Carex peckiiSEDGE
Carex pedunculataSEDGE
Carex pellitaSEDGE
Carex pensylvanicaSEDGE
Carex plantagineaSEDGE
Carex platyphyllaBROAD-LEAVED SEDGE
Carex praegracilisSEDGE
Carex praireaSEDGE
Carex prasinaSEDGE
Carex praticolaSEDGE
Carex projectaSEDGE
Carex pseudo-cyperusSEDGE
Carex radiataSTRAIGHT-STYLED WOOD SEDGE
Carex retroflexaSEDGE
Carex retrorsaSEDGE
Carex richardsoniiRICHARDSON'S SEDGE
Carex roseaCURLY-STYLED WOOD SEDGE
Carex rossiiROSS' SEDGE
Carex rostrataSEDGE
Carex sartwelliiSEDGE
Carex scabrataSEDGE
Carex schweinitziiSEDGE
Carex scirpoideaBULRUSH SEDGE
Carex scopariaSEDGE
Carex seorsaSEDGE
Carex siccataSEDGE
Carex sparganioidesSEDGE
Carex spicataSEDGE
Carex sprengeliiSEDGE
Carex squarrosaSEDGE
Carex sterilisSEDGE
Carex stipataSEDGE
Carex stramineaSTRAW SEDGE
Carex strictaSEDGE
Carex suberectaSEDGE
Carex swaniiSEDGE
Carex sychnocephalaLONG-BEAKED SEDGE
Carex sylvaticaSEDGE
Carex teneraSEDGE
Carex tenuifloraSEDGE
Carex tetanicaSEDGE
Carex texensisSEDGE
Carex tinctaSEDGE
Carex tonsaSEDGE
Carex tribuloidesSEDGE
Carex trichocarpaHAIRY-FRUITED SEDGE
Carex trispermaSEDGE
Carex tuckermaniiSEDGE
Carex typhinaCAT-TAIL SEDGE
Carex umbellataSEDGE
Carex utriculataSEDGE
Carex vaginataSEDGE
Carex vesicariaSEDGE
Carex virescensSEDGE
Carex viridistellataSEDGE
Carex viridulaSEDGE
Carex vulpinoideaSEDGE
Carex wiegandiiWIEGAND'S SEDGE
Carex woodiiSEDGE
Cladium mariscoidesTWIG-RUSH
Cyperus acuminatusUMBRELLA SEDGE
Cyperus bipartitusBROOK NUT SEDGE
Cyperus diandrusUMBRELLA SEDGE
Cyperus engelmanniiUMBRELLA SEDGE
Cyperus erythrorhizosUMBRELLA SEDGE
Cyperus esculentusYELLOW NUTSEDGE
Cyperus flavescensYELLOW FLAT SEDGE
Cyperus fuscusSEDGE
Cyperus houghtoniiSMOOTH SAND SEDGE
Cyperus iriaRICEFIELD FLATSEDGE
Cyperus lupulinusSLENDER SAND SEDGE
Cyperus odoratusUMBRELLA SEDGE
Cyperus schweinitziiROUGH SAND SEDGE
Cyperus squarrosusUMBRELLA SEDGE
Cyperus strigosusLONG SCALED NUT SEDGE
Dulichium arundinaceumTHREE-WAY SEDGE
Eleocharis acicularisSPIKE-RUSH
Eleocharis atropurpureaPURPLE SPIKE-RUSH
Eleocharis compressaFLATTENED SPIKE RUSH
Eleocharis ellipticaGOLDEN-SEEDED SPIKE RUSH
Eleocharis engelmanniiENGELMANN'S SPIKE-RUSH
Eleocharis equisetoidesHORSETAIL SPIKE RUSH
Eleocharis erythropodaSPIKE-RUSH
Eleocharis flavescensSPIKE-RUSH
Eleocharis geniculataSPIKE-RUSH
Eleocharis intermediaSPIKE-RUSH
Eleocharis melanocarpaBLACK-FRUITED SPIKE-RUSH
Eleocharis microcarpaSMALL-FRUITED SPIKE-RUSH
Eleocharis nitidaSLENDER SPIKE-RUSH
Eleocharis obtusaSPIKE-RUSH
Eleocharis ovataSPIKE-RUSH
Eleocharis palustrisSPIKE-RUSH
Eleocharis parvulaDWARF SPIKE-RUSH
Eleocharis quadrangulataFOUR-SIDED SPIKE-RUSH
Eleocharis quinquefloraSPIKE-RUSH
Eleocharis radicansSPIKE-RUSH
Eleocharis robbinsiiSPIKE-RUSH
Eleocharis rostellataSPIKE-RUSH
Eleocharis tricostataTHREE-RIBBED SPIKE-RUSH
Eriophorum angustifoliumNARROW-LEAVED COTTON-GRASS
Eriophorum gracileSLENDER COTTON-GRASS
Eriophorum tenellumCOTTON-GRASS
Eriophorum vaginatumCOTTON-GRASS
Eriophorum virginicumTAWNY COTTON-GRASS
Eriophorum viridi-carinatumGREEN-KEELED COTTON-GRASS
Fimbristylis autumnalisAUTUMN SEDGE
Fimbristylis puberulaCHESTNUT SEDGE
Fuirena pumilaUMBRELLA-GRASS
Lipocarpha micranthaDWARF-BULRUSH
Rhynchospora albaBEAK-RUSH
Rhynchospora capillaceaBEAK-RUSH
Rhynchospora capitellataBEAK-RUSH
Rhynchospora fuscaBEAK-RUSH
Rhynchospora macrostachyaTALL BEAK-RUSH
Rhynchospora nitensSHORT-BEAKED BALD RUSH
Rhynchospora recognitaGLOBE BEAK-RUSH
Rhynchospora scirpoidesBALD-RUSH
Schoenoplectiella halliiHALL'S BULRUSH
Schoenoplectiella mucronataBOG BULRUSH
Schoenoplectiella purshianaPURSH'S TUFTED BULRUSH
Schoenoplectiella smithiiBULRUSH
Schoenoplectus acutusHARDSTEM BULRUSH
Schoenoplectus americanusOLNEY'S BULRUSH
Schoenoplectus heterochaetusBULRUSH
Schoenoplectus pungensTHREESQUARE
Schoenoplectus subterminalisBULRUSH
Schoenoplectus tabernaemontaniSOFTSTEM BULRUSH
Schoenoplectus torreyiTORREY'S BULRUSH
Scirpus atrocinctusWOOL-GRASS
Scirpus atrovirensBULRUSH
Scirpus cyperinusWOOL-GRASS
Scirpus expansusBULRUSH
Scirpus georgianusBULRUSH
Scirpus hattorianusMOSQUITO BULRUSH
Scirpus microcarpusBULRUSH
Scirpus pedicellatusWOOL-GRASS
Scirpus pendulusBULRUSH
Scleria paucifloraFEW-FLOWERED NUT-RUSH
Scleria reticularisNETTED NUT-RUSH
Scleria triglomerataTALL NUT-RUSH
Scleria verticillataNUT-RUSH
Trichophorum alpinumBULRUSH
Trichophorum cespitosumBULRUSH
Trichophorum clintoniiCLINTON'S BULRUSH

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 29, 2014. http://michiganflora.net/family.aspx?id=CYPERACEAE.