Natans: Answers to key questions in Rushes, Bulrushes & Pondweeds plus the remaining Monocots  of Saskatchewan by V.L. Harms, A.L. Leighton and M.A. Vetter leading to this species. The answers are in the order you would normally work through the key.

	Stigmas 1; mature fruit bodies usually <5 mm long, ellipsoidal, fusiform or obovoid, tapering to beaks (+/- beakless in S. hyperboreum), stipitate or subsessile, 1-locular and 1-seeded; inflorescences branched or unbranched; leaves emergent or floating; NOT [Stigmas usually 2, occasionally 1 on some flowers; mature fruit bodies 5-10 mm long, obpyramidal, abruptly contracted to beaks, sessile, usually 2-locular and 2-seeded; inflorescences usually branched; leaves emergent]
	Mature fruiting heads usually <10 mm wide; staminate heads single or apparently so (rarely 2); fruit bodies subsessile; inflorescences unbranched; NOT [Mature fruiting heads >10 mm wide; staminate heads usually 2 or more (1 in S. glomeratum); fruit bodies distinctly stipitate; inflorescences unbranched or branched]
	Lowermost pistillate heads axillary, usually sessile, sometimes pedunculate; mature fruit short beaked, the beaks 0.5-1.5 mm long; staminate heads remote from uppermost pistillate head; leaves 2-8 mm wide, thin, translucent, usually dark green; NOT [Lowermost pistillate heads supra-axillary; mature fruit essentially beakless, the beaks <0.5 mm long or absent; staminate heads contiguous or not with uppermost pistillate head; leaves 1-5 mm wide, rather thick, opaque, yellowish green.]