Sartwellii: Answers to key questions in Sedges (Carex) of Saskatchewan, Fascicle 3, Flora of Saskatchewan by Anna Leighton leading to this species. The answers are in the order you would normally work through the key. 

	Stigmas 2; achenes lenticular; NOT [Stigmas 3; achenes three-sided, occasionally terete, though their shape may be concealed by flattened perigynia.]
	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]
	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.]
	Culms single, or a few together, well-spaced along conspicuous rhizomes or stolons.  NOT [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.]
	Culms growing directly from 1-3 mm wide, horizontal rhizomes; NOT [Culms growing singly from stolons formed by reclining vegetative shoots that elongate horizontally and become overgrown by moss; rhizomes short and rarely collected; perigynia 2.5-3.5 (4.5) mm long, red-brown to dark brown, shiny, faintly to prominently red-brown nerved; plants of sphagnum bogs]
	Some spikes may be indistinguishable at tip of inflorescence, but usually at least lower spike is visually distinct (except in oft-collected, immature heads of C. duriuscula); perigynia not two-toned as in C. maritima; plants not restricted to far north.  NOT [All spikes indistinguishable in an ovoid to +/- round head; perigynia irregularly two-toned (pale on lower half, darker on upper half and beak); plants of gravel substrates in far north.]
	Perigynia usually less than 4 mm long, or if longer, then pistillate scales completely covering perigynia; all spikes in inflorescence alike in sex: androgynous in monoecious plants, unisexual in dioecious plants.  NOT [Perigynia (3.5) 4-6.5 mm long; pistillate scales usually shorter and narrower than perigynia; spikes in inflorescence similar in appearance but unlike in sex: terminal androgynous, gynecandrous or pistillate; middle +/- staminate; lower +/- pistillate.]
	Ventral strip opaque and green-nerved to hyaline summit; two small warts often present at junction of blade and leaf-sheath; spikes closely packed but distinguishable, regularly arranged, uniformly ascending at an angle of about 45 degrees and arrayed in definite ranks; plants monoecious with androgynous spikes.  NOT [Ventral strip translucent and nerveless (though underlying nerves on the culms may be visible through strip); no special warts at junction of blade and leaf-sheath; spike density variable with spikes at various angles and less visibly ranked; plants monoecious with androgynous spikes, or dioecious with unisexual spikes.]