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Stigmas 2;
achenes lenticular; NOT [Stigmas 3; achenes three-sided, occasionally
terete, though their shape may be concealed by flattened perigynia.] |
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Spikes 2
or more per culm, terminal and lateral; spike bracts present on lateral
spikes; lowest spike bracts usually evident, often conspicuous, even in
compact heads composed of densely bunched and indistinguishable spikes
(except in C. maritima, C. chordorrhiza and C. microptera); NOT [Spikes
1 per culm, terminal; spike bracts absent] |
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Individual
spikes distinguishable in an open inflorescence, or indistinguishable in
a compact head; spikes in any one inflorescence alike in appearance due
to their similar composition (i.e. all are gynecandrous, androgynous,
pistillate or staminate), sessile. NOT [Individual spikes
distinguishable in an open inflorescence (densely bunched in C.
bicolor); spikes in any one inflorescence either markedly different in
appearance (with terminal spike staminate and lateral spikes
pistillate), or subtly different in appearance (with terminal spike
gynecandrous and lateral spikes pistillate), sessile or stalked.] |
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Culms
loosely to densely cespitose (occasionally mat-forming rather than in
discrete clumps); rhizomes, if present, usually short with culms arising
close together along them. NOT [Culms single, or a few together,
well-spaced along conspicuous rhizomes or stolons.] |
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Spikes
gynecandrous, (terminal spikes may be staminate in SK material of C.
mackenziei; pistillate or staminate spikes occur in Sect. Stellulatae, a
group distinguished by spongy tissue filling lower one-third to one-half
of the perigynium); if heads have indistinguishable spikes, the heads
are usually +/- as wide as they are long and usually widest in middle or
toward base. NOT [Spikes androgynous, (lateral spikes occasionally
pistillate in C. prairea); if heads have indistinguishable spikes, the
heads are usually oblong to elongate in shape.] |
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Lower 3 or
4 spike bracts usually scale-like or bristle-like; if lowest is long and
leaf-like, then it is shorter than half the culm length or it appears to
be an extension of the culm to which inflorescence is attached laterally
(as in C. athrostachya); perigynia various. NOT [Lower 3 or 4
spike bracts long, pale-green and leaf-like; lowest bract 5-15 (20) cm
long, usually half to fully as long as culm below inflorescence;
perigynia 5 mm long or longer, narrowly lanceolate.] |
|
Perigynium
margins flattened as a narrow or wide wing for all or part of perigynium
length (wing reduced to raised thickened nerve along body in C. adusta);
mature achene narrower than perigynium body; beak present (though may be
ill-defined); neither perigynium base nor perigynium wall thickened with
spongy tissue. NOT [Perigynium distinctly wingless though margins
may be thickened as rounded or raised nerves; mature achene filling
width of perigynium body; perigynium base or wall thickened by spongy
tissue or cells; beak present or absent.] |
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Spike
bracts usually shorter, or a bit longer than the inflorescence; if much
longer then clearly positioned beneath spike and appearing lateral
rather than extending culm-like beyond inflorescence. NOT [Lowest
spike bract distinctly longer than the inflorescence and appearing to be
an extension of culm with inflorescence attached to one side rather than
at tip.] |
|
Perigynia
5.2 mm long or less (occasionally to 6 mm); distance from tip of beak to
top of achene 3 mm at most; inflorescence nodding or erect; species not
confined to Cypress Hills. NOT [Perigynia 6-8 mm long
(occasionally as short as 5.5 mm); distance from tip of beak to top of
achene 3.2–4.6 mm; inflorescence stiffly erect; Cypress Hills only.] |
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Spikes
distinguishable, or indistinguishable in a compact head; perigynia at
most 3 times longer than wide (C. praticola occasionally narrower but
then pistillate scales covering perigynia); other features variable.
NOT [Spikes distinguishable; perigynia usually 4 times longer than wide,
3-4 (4.7) mm long and seldom over 1 mm wide; scales distinctly shorter
than perigynia; veins absent or faint on both surfaces of perigynia.] |
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Perigynium
body narrower, somewhat contracted or tapering into beak; scale width
and perigynium color variable. NOT [Perigynium body orbicular,
abruptly contracted into beak, remaining green until turning tan at
maturity; pistillate scales one-third to two-fifths as wide as
perigynia.] |
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Scales not
resembling wax paper, color various; perigynia not yellow at base.
NOT [Scales scarious-translucent, resembling wax paper, whitish to
yellowish with pale (never green) prominent midrib; perigynia yellow at
base, faintly nerved.] |
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Pistillate
scales, at least those in the middle and upper part of spike, distinctly
narrower and/or shorter than the mature perigynia, revealing margins
and/or beak. NOT [Pistillate scales throughout the spike similar
in size and shape to the mature perigynia, and more or less concealing
them.] |
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Spikes
indistinguishable in a dense head that is truncate and widest at base,
and approximately as wide as it is long. NOT [Spikes
distinguishable in a compact to elongate inflorescence.] |