| More than two spikes per culm |
| All spikes in any one inflorescence are the same |
| Plants cespitose, do NOT have stolons or long rhizomes |
| Spikes gynecandrous (look for old filaments at base of spikes) |
| Lower 3 or 4 spike bracts NOT long, green, and leaf-like (i.e. NOT C. sychnocephala, see picture) |
| Perigynium winged (see image labeled "Perigynium" under C. microptera in colinherb.com). C. adusta is a bit of an exception,
see description in book, has not been collected south of Saskatchewn River.
|
| If lowest spike bract extends far beyond inflorescence, moist prairie or dried slough
bottoms
| C. athrostachya |
|
| If peryginia 6-8 mm long with long narrow beak, Cypress Hills only
| C. petasata |
|
| If peryginia very narrow, less than 1 mm wide
| C. crawfordii |
|
| If peryginia round with short, abrupt beak
| C. brevior |
|
| If scales translucent with NON-green midrib, peryginia yellow at base
| C. xerantica |
|
| If scales same size and shape as mature perigynia and mostly concealing them
| If lowest spike bract as long as or several times longer than inflorescence,
sandy disturbed sites
| C. adusta |
|
| If flat, green, winged margins of perigynia petering out below teeth, style visibly protruding from beak
| C. praticola |
|
| If flat, green, winged margins of perigynia extends length of beak and up
along teeth, style scarcely protruding from beak
| C. foenea |
|
|
| If scales (at least in middle and upper part of spike) distinctly shorter and/or
narrower than mature perigynia
| If spikes indistinguishable in a dense head that is truncate, widest at base,
and about as wide as long
| C. microptera |
|
| If leaf sheaths lacking wings
| If spikes separate to loosely overlapping at base of inflorescence
| C. tenera |
|
| If spikes densely overlapping at base of inflorescence
| C. bebbi |
|
|
| If leaf sheaths possessing wings
| If spikes overlapping below to densely bunched above, perigynia ovate-elliptic, plant rare
| C. cristatella |
|
| If spikes arranged like beads on a necklace, perigynia lanceolate,
plant very rare in Pasquia Hills
| C. projecta |
|
|
|