Microcarpus: 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. 

Bristles shorter to only somewhat longer than achenes, not or only slightly projecting beyond scales and not giving mature inflorescences a woolly appearance; spikelets usually in clusters, occasionally solitary; scales to 3.4 mm long including tip/awn.  NOT [Bristles much longer than achenes, projecting well beyond the scales giving mature inflorescences a woolly appearance; most spikelets attached individually to branches, some in small clusters; scales to 1.8 mm long including tip.]

Scale apices unawned, usually apiculate or mucronate with a point up to 0.2 mm long; styles usually bifid, occasionally trifid; spikelets 2 - 8 mm long, in clusters of 3 - 18, occasionally solitary; achenes 0.8 - 1 mm wide, biconvex to plano-convex; rhizomes long, reddish, with conspicuous nodes and internodes; culms solitary.  NOT [Scale apices short awned, with awns 0.4 - 0.6 (1.2) mm long; styles trifid; spikelets 4 - 5 mm long, in dense globose clusters of 12 - 25 (50+); achenes 0.4 - 0.6 mm wide, trigonous or plano-convex; rhizomes short, tough, fibrous; culms tufted.]

Scirpus: 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 genus. The answers are in the order you would normally work through the key. 

	Flowers and achenes naked in the axils of scales, not enclosed in a sac; flowers usually perfect (sometimes some flowers imperfect in Cyperus, Rhynchospora and Cladium).  NOT [Flowers and achenes enclosed in a sac (perigynium) borne in the axils of scales; flowers imperfect.]
	Perianth bristles absent or up to 6 per flower; if more than 6, then only somewhat longer than the achenes.  NOT [Perianth bristles usually more than 10 per flower, much longer than the achenes, conspicuously elongated to over 10 mm long in fruit stage and usually obscuring most scales in spikelets.]
	Inflorescence not a solitary, terminal spike; if solitary, terminal and spike-like, then inflorescence +/- terete.  NOT [Inflorescence a compressed, solitary, terminal spike bearing few-flowered spikelets attached in 2 rows.]
	Inflorescence usually with > 1 spikelet; if only 1 spikelet present, then inflorescence bract usually 10 - 200 mm long (but as short as 7 mm in Schoenoplectus subterminalis) and achenes 2 - 3.5 mm long.  NOT [Inflorescence a solitary terminal spikelet; inflorescence bracts absent or up to 8 mm long and only slightly longer than the spikelet; achenes usually <= 2 mm long (up to 2.3 mm in Eleocharis quinqueflora).]
	Achenes lacking a tubercle but sometimes beaked.  NOT [Achenes with a narrowly triangular tubercle.]
	Scales of spikelets spirally arranged; spikelets terete.  NOT [Scales of spikelets 2-ranked; spikelets flattened or 4-sided.]
	Plants without the following combination of characteristics.  NOT [Culms tall and slender, 30 - 100 cm high and 1 - 2 mm wide; inflorescences with stiffly ascending primary and secondary branches supporting 100 - 1,000 spikelets in compact clusters; achenes terete with bases discoid, truncate, impressed and flared.]
	Inflorescences subtended by 2 or more leaf-like, erect to spreading bracts; longest bracts exceeding the inflorescence; leaves basal and cauline, or all cauline with cauline leaf blades well developed.  NOT [Inflorescences not subtended by leaf-like bracts, the proximal bract terete, trigonous or thickly C-shaped in cross-section and resembling a continuation of the culm (making the inflorescence appear to be attached to the side of the culm although the bract may be pushed aside in Amphiscirpus as the spikelets mature); longest bracts exceeding the inflorescence or not; usually all leaves basal with blades often much shorter than their sheaths.]
	Spikelets numerous (50 - 500 per inflorescence) and small (2 - 8 mm long (ours), 1- 3.5 mm wide); anthers ca. 1 mm long (ours); scales glabrous, apiculate, mucronate or with awns to 0.6 (1.2) mm long (ours); achenes 0.6 - 1.8 mm long; culms not cormose at base.  NOT [Spikelets fewer (ours < 40 per inflorescence) and large (7 - 40 mm long (ours), (4) 6 - 10 mm wide); anthers 2 - 4+ mm long; scales puberulent to glabrescent with awns 1 - 3 mm long; achenes 2.3 - 5.5 mm long; culms cormose at base.]

Cyperaceae: Answers to key questions in Budd's Flora leading to this family. 

	plants not aquatic, or if growing in water, most of the plant emersed; NOT [plants aquatic, floating or submerged, with floating leaves or emersed inflorescence]
	culms usually solid; NOT culms usually hollow]
	leaves three-ranked; NOT [leaves two-ranked]
	inflorescence NOT [a dense, single, cylindrical spike 8-15 cm long, 1-2.5 cm thick],  if a single spike, less than 1 cm thick
	flowers not in globular heads; NOT [flowers in globular heads, the upper ones staminate, the lower ones pistillate]
	flowers solitary in the axil of a single bract (scale); NOT [flowers enclosed in two-ranked bracts with the lowest (glumes) empty]
	perianth absent or inconspicuous, not in two whorls; NOT [perianth present, conspicuous, in two whorls of 3 segments each, often brightly colored]
	perianth reduced to bristles or scales or lacking; NOT [perianth reduced to minute lodicules or lacking]