Achene enclosed in a
perigynium (a
sac -like structure); [subfamily
Caricoideae , tribe
Cariceae ]
Achene not enclosed in a
perigynium .
Scales obviously and strongly
distichously imbricate ;
spikelets either aggregated into
spikes or heads (
Cyperus, Dulichium, Schoenus ), or solitary (
Abildgaardia ); [subfamily
Cyperoideae ].
Spikelets solitary and terminal (rarely 2-4); of FL peninsula in our area]
Spikelets aggregated into terminal or
axillary spikes or heads; [widespread in our area].
Inflorescence axillary ; leaves predominantly
cauline , conspicuously 3-ranked;
perianth bristles subtending the
achene 6-9; [tribe
Dulichieae ]
Inflorescence terminal, more-or-less
scapose (though immediately subtended by leafy
bracts ); leaves predominantly
basal , not 3-ranked;
perianth bristles absent (
Cyperus ) or present (
Schoenus ); [tribe
Cypereae ].
Achene (when ripe) bony and white;
style base persistent on the summit of the
achene , forming a differently-textured or differently-colored
tubercle ;
spikelets all
unisexual , the
pistillate spikelets 1-flowered, the
staminate spikelets several-flowered; [subfamily
Sclerioideae , tribe
Sclerieae ]
Achene mostly brown, black, or tan;
style base either
persistent as a differentiated
tubercle (
Bulbostylis, Eleocharis, Rhynchospora ) or not (
Cladium , Eriophorum, Fuirena, Is olepis, Cyperus , Schoenoplectus, Scirpus, Trichophorum );
spikelets mostly or all
bisexual ; [subfamily
Cyperoideae ].
Style base persistent as a differentiated
tubercle (this small and inconspicuous in
Bulbostylis and some spp. of
Rhynchospora ).
Leaves consisting of bladeless
sheaths ;
spikelet 1 per stem, terminal (very rarely
proliferating and with > 1
spikelet ); [tribe
Eleocharideae ]
Leaves with well-developed
blades ;
spikelets few to many per stem, usually subtended by
foliaceous bracts .
Perianth bristles absent;
spikelets several-many-flowered; leaves
capillary ; [tribe
Abildgaardieae ]
Perianth bristles present (rarely absent in species without
capillary leaves);
spikelets 1-2-flowered (several-many-flowered in some species without
capillary leaves); leaves
capillary to broad; [tribe
Schoeneae ]
Achene not subtended by a modified
perianth of
bristles or
scales (in addition to the
scales of the
spikelets ).
Involucral bracts 1-3, the lowest erect, appearing like a continuation of the
culm , the
inflorescence therefore appearing
lateral .
Achenes 0.5-0.7 mm long, 1.8-3× as long as wide, minutely
papillose in
longitudinal lines; [tribe
Cypereae ]
Achenes 1.2-1.5 mm long, 1-1.4× as long as wide, minutely pitted or transversely
rugose .
Achenes minutely pitted in
longitudinal lines; [tribe
Cypereae ]
Spikelets in a
loose cluster (not
spherical )
Involucral bracts 2-several, spreading, the
inflorescence therefore appearing terminal.
Plants diminutive, to 5 dm tall; leaves 3-15 cm long, < 1 mm wide; [tribe
Abildgaardieae ]
Plants moderate to very robust, (3-) 5-30 dm tall; leaves 30-150 cm long, 1.5-15 mm wide.
Flowers 1-2 per
spikelet ; [tribe
Schoeneae ]
Flowers several-many per
spikelet .
Style fimbriate ; leaves 0.5-5 mm wide; [tribe
Abildgaardieae ]
Style smooth; leaves (2-) 5-18 mm wide; [tribe
Scirpeae ]
Achene subtended by a modified
perianth of either
bristles , 3 stalked paddle-like
scales , or 1-2 broad-based
scales (in addition to the
scales of the
spikelets ).
Achene subtended by stalked paddle-like
scales or broad-based
scales .
Achene lacking a
perianth , but subtended by 1-2 broad-based
scales ; plants 0.5-3 dm tall; [tribe
Cypereae ]
Achene subtended by a
perianth of 3 stalked paddle-like
scales ; plants 2-7 dm tall; [tribe
Fuireneae ]
Achene subtended by
bristles .
Bristles 10-many, > 5× as long as the
achene , white to
tawny , straight; [tribe
Scirpeae ]
Bristles 1-6, usually < 4× as long as the
achene , brown, straight or conspicuously twisted (twisted if > 3× as long as the
achene ).
Involucral bracts lacking, or consisting only of the slightly modified
basal scales of the solitary and terminal
spikelet ; [of hillsides, upland forests, or
cliffs ; never (in our area) in
marshes ,
bogs , or streambeds]; [tribe
Scirpeae ]
Involucral bracts present, consisting either of a single, erect
bract appearing as a continuation of the
culm (the
inflorescence thus appearing
lateral ) or of 2 or more spreading,
foliaceous bracts (the
inflorescence thus appearing terminal); [of
marshes ,
bogs , streambeds, ditches, or (rarely) terrestrial or on rock outcrops].
Main
involucral bract 1 (rarely 2), erect, appearing as a continuation of the
culm (the
inflorescence thus appearing
lateral , though in some species the longer
inflorescence branches may overtop the
bract ); [tribe
Fuireneae ]
Achenes rugulose ; plants annual
Achenes smooth; plants perennial
Main
involucral bracts 2-8, spreading and
foliaceous (the
inflorescence thus appearing terminal).
Spikelets 10-40 mm long, 6-12 mm in diameter, (1-) 2-40 (-50) per
culm ; [tribe
Fuireneae ]
Spikelets 2.5-19 mm long, 2-4 mm in diameter, usually > 50 per
culm ; [tribe
Scirpeae ]
Main
involucral bracts 2-8, spreading and
foliaceous (the
inflorescence thus appearing terminal);
rhizomes bearing
ovoid tubers ;
bristles persistent on the
achene ;
achenes 2.5-5 mm long (including body and
apiculus )
Main
involucral bract 1 (rarely with an additional 1-2
lateral bracts ), erect and
terete or
triangular , appearing as a continuation of the
culm (the
inflorescence thus appearing
lateral , though in some species the longer
inflorescence branches may overtop the
bract );
rhizomes not bearing
tubers ;
bristles falling from the
achene ;
achenes 1.0-4.5 mm long (including body and
apiculus ).
Spikelets on
stalks of varying lengths, at least some clearly not
sessile .
Culms distinctly
triangular in cross-section, more sharply so above than below, nearly
terete near the
base ; [section
Malacogeton ]
Culms terete throughout, or obscurely
triangular above; [section
Schoenoplectus ].
Culms firm, not easily
compressed ;
scales 3-4 mm long.
Achenes biconvex (or rarely weakly
trigonous ),
styles 2;
spikelets 3-190, usually in clusters of 2-8 on
pedicels , sometimes solitary, but never all solitary throughout
inflorescence ;
bristles usually 6 (5-7), of
equitant or differing lengths;
scales usually with
copious red-brown dots
Achenes trigonous ,
styles 3;
spikelets 5-30, mostly solitary or rarely 2 together borne on the same
pedicels ;
bristles 4, of two conspicuous lengths;
scales without
copious red-brown dots (sometimes obscurely
dotted )
Culms soft and
spongy , easily compressible;
scales (2.0-) 2.5-3.0 (-3.5) mm long.
Spikelets all
sessile , in a cluster at one point (rarely with 1 or 2 short branches to 5 mm long).
Spikelet solitary; leaves numerous; plant usually aquatic, the
culms and leaves
flaccid , supported by the water; [section
Malacogeton ]
Spikelets (1-) 2-several; leaves 1-4; usually of wet places, but the
culms stiff and erect, not floating.
Rhizomatous perennial;
culms triangular in cross-section, usually 5-20 dm tall.
Leaves elongate, > ½ as long as the
culms ;
achenes trigonous ;
styles 3-branched; [section
Malacogeton ]
Leaves short, < ½ as long as the
culms ;
achenes plano-
convex ;
styles 2 (-3) branched; [
Schoenoplectus pungens complex of section
Schoenoplectus ].
Sides of the
culm strongly
concave , wing-angled;
culms 3-10 mm in diameter; main
involucral bract 1-2.5 (-6) cm long;
spikelet scale with
apical notch 0.1-0.4 mm deep
Sides of the
culm flat, slightly
concave , or slightly
convex ;
culms 1-6 mm in diameter; main
involucral bract (1-) 3-20 cm long;
spikelet scale with
apical notch (0.3-) 0.5-1 mm deep.
Spikelets 3-35;
achenes 1.9-2.6 mm long,
biconvex ;
styles 2-fid
Spikelets 1-5 (-10);
achenes (2.0-) 2.5-3.5 mm long,
biconvex or
trigonous ;
styles 2-3-fid.
Styles 3-fid;
achenes thickly
lenticular to bluntly
trigonous ;
spikelet scales brown to tan