| CAREX KEY 
      FOR SPECIES FOUND IN SASKATCHEWAN | 
  
   
    | * The reader is 
      also referred to Carex in Saskatchewan by J. Hudson (1977) and 
      Flora of Alberta edited by J. Packer (1983). | 
  
   
    |   | 
      | 
  
   
    | 1 Leaves mostly basal; spike one per 
      stem, terminal; flowers attached to main stem | 
    2  | 
  
   
    | 1 Stem leaves usually present; spikes 
      usually two or more per stem, terminal and/or lateral; flowers may not all 
      be attached to main stem | 
    11  | 
  
   
    |   | 
      | 
  
   
    2 Stigmas 2; achenes lens-shaped
  | 
    3  | 
  
   
    | 2 Stigmas 3; achenes triangular | 
      5  | 
  
   
    |   | 
      | 
  
   
    | 3 Rhizome long, slender; stems solitary 
      or few; spikes unisexual, plant with only male or only female inflorescences | 
    C. gynocrates  | 
  
   
    | 3 Rhizomes slender or obliquely ascending, 
      if slender, runners present; stems tufted; spikes bisexual, male flowers 
      above or below female flowers in the same spike | 
    4  | 
  
   
    |   | 
      | 
  
   
    | 4 Plant tufted with rootstocks obliquely 
      ascending; spikes bisexual, male flowers above female flowers in the same 
      spike | 
    C. capitata ssp. capitata  | 
  
   
    | 4 Plant caespitose with slender rhizomes 
      and runners; spikes bisexual, female flowers above male flowers in the same 
      spike | 
    C. mackenziei  | 
  
   
    |   | 
      | 
  
   
    | 5 Plant with male and female flowers 
      on separate plants; perigynia somewhat hairy; not tufted | 
    C. scirpoidea  | 
  
   
    | 5 Plant with male and female flowers 
      on the same plant, male flowers above female flowers in the same spike; 
      perigynia may or may not be hairy, if hairy, plant tufted | 
    5  | 
  
   
    |   | 
      | 
  
   
    | 6 Female flower scales deciduous, 
      scale-like; perigynia short-stalked, spreading or reflexed | 
    C. pauciflora  | 
  
   
    | 6 Female flower scales persistent, 
      scale-like or leaf-like; perigynia sessile, not spreading or reflexed | 
    7  | 
  
   
    |   | 
      | 
  
   
    | 7 Female flower scales green, leaf-like | 
    8  | 
  
   
    | 7 Female flower scales straw-coloured, 
      brownish or green, scale-like | 
    9  | 
  
   
    |   | 
      | 
  
   
    | 8 Perigynium 4 – 6 mm long; 
      beak 2 – 3 mm long | 
    C. backii  | 
  
   
    | 8 Perigynium ~ 4 mm long; beak ~ 1 
      mm long | 
    C. saximontana  | 
  
   
    |   | 
      | 
  
   
    | 9 Perigynia beakless, many nerved, 
      tip rounded | 
    C. leptalea  | 
  
   
    | 9 Perigynia beaked, few nerved, tip 
      not rounded | 
    10  | 
  
   
    |   | 
      | 
  
   
    | 10 Perigynia leathery, shining; rhizome 
      long; prairie species | 
    C. obtusata  | 
  
   
    | 10 Perigynia minutely hairy, dull; 
      rhizome short or absent, plant tufted; dry grasslands | 
    C. filifolia  | 
  
   
    |   | 
      | 
  
   
    | 11 Stigmas 2; achenes lens-shaped | 
    12  | 
  
   
    | 11 Stigmas 3; achenes triangular | 
    65  | 
  
   
    |   | 
      | 
  
   
    | 12 At least some of the lateral spikes 
      stalked | 
    13  | 
  
   
    | 12 Lateral spikes all sessile | 
    21  | 
  
   
    |   | 
      | 
  
   
    | 13 Perigynia 3 – 5.5 mm long, 
      shining, inflated, prominently ribbed; beak tubular; style continuous with 
      achene or deciduous | 
    C. saxatilis  | 
  
   
    | [* C. physocarpioides (C. 
      saxatilis x C. utricularia. Infrequent, sterile. With intermediate 
      characteristics.] | 
     | 
  
   
    | 13 Perigynia 2 – 3 (4) mm long, 
      not inflated or shining, may be ribbed; beakless; style jointed or continuous 
      with achene | 
    14  | 
  
   
    |   | 
      | 
  
   
    | 14 Bract at base of inflorescence 
      distinctly sheathing; male-flowered spike 1; perigynia nearly round in cross 
      section, rounded at tip | 
    15  | 
  
   
    | 14 Bract at base of inflorescence 
      nearly sheathless; male-flowered spikes 1 or more; perigynia convex on both 
      sides, sometimes flattened, acute at tip | 
    17  | 
  
   
    |   | 
      | 
  
   
    | 15 Lowest bracts as long as or shorter 
      than inflorescence, short-sheathing, may have ear-like lobes; scales purplish-black | 
    C. bicolor  | 
  
   
    | 15 Lowest bract leaf-like, as long 
      as or longer than inflorescence, long-sheathing, ear-like lobes lacking; 
      scales various colours | 
    16  | 
  
   
    |   | 
      | 
  
   
    | 16 Perigynia whitish, dry, ribbed, 
      crowded in spike; scales reddish-brown to purplish | 
    C. garberi  | 
  
   
    | 16 Perigynia golden-yellow to brown, 
      fleshy, ribbed, not crowded in spike; scales whitish to orangish-brown | 
    C. aurea  | 
  
   
    |   | 
      | 
  
   
    | 17 Plant tufted; rhizomes lacking; 
      leaves 1 – 3 mm wide; perigynia distinctly nerved | 
    C. lenticularis var. lenticularis  | 
  
   
    | 17 Plant not tufted; rhizomes present; 
      leaves 2 – 8 mm wide; perigynia nerved or nerveless | 
    18  | 
  
   
    |   | 
      | 
  
   
    | 18 Perigynia 0 – 50 nerved on 
      each face, somewhat inflated, with short bumps on surface  | 
    C. paleacea  | 
  
   
    | 18 Perigynia nerveless, dotted with 
      pits or glands | 
    19  | 
  
   
    |   | 
      | 
  
   
    | 19 Female flower scales acute; achenes 
      indented on one side near middle  | 
    C. subspathacea  | 
  
   
    | 19 Female flower scales obtuse to 
      acute to awned; achenes not indented | 
    20  | 
  
   
    |   | 
      | 
  
   
    | 20 Lowest bract leaf-like, equal to 
      or longer than inflorescence | 
    C. aquatilis  | 
  
   
    | 20 Lowest bract bristle-like, shorter 
      than inflorescence | 
    C. bigelowii  | 
  
   
    |   | 
      | 
  
   
    | 21 Stems single or loosely tufted 
      (few together) from rhizomes or reclining stems | 
    22  | 
  
   
    | 21 Stems densely tufted; rhizomes 
      short | 
    29  | 
  
   
    |   | 
     | 
  
   
    | 22 Stems reclining, branching, long 
      prostrate stems with erect flowering branches in axils of dried up leaves; 
      sphagnum bogs | 
    C. chordorriza  | 
  
   
    | 22 Stems erect or ascending; habitats 
      various | 
    23  | 
  
   
    |   | 
     | 
  
   
    | 23 Plants usually with male and female 
      flowers on separate plants, spikes either completely male-flowered or female-flowered | 
    24  | 
  
   
    | 23 Plants with male and female flowers 
      on the same plant, male flowers above or below female flowers in the same 
      spike | 
    26  | 
  
   
    |   | 
      | 
  
   
    | 24 Stems obtusely triangular; slender 
      brownish, scaly rhizomes; plants of dry habitats | 
    C. douglasii  | 
  
   
    | 24 Stems sharply triangular; rhizomes 
      stout or slender; plants of wet habitats | 
    25  | 
  
   
    |   | 
     | 
  
   
    | 25 Perigynia brown, convex on both 
      sides; rhizomes slender, brown; calcareous bogs; rare | 
    C. simulata  | 
  
   
    | 25 Perigynia becoming blackish, convex 
      on one side; rhizomes thick, black; moist prairies and sloughs; common | 
    C. praegracilis  | 
  
   
    |   | 
     | 
  
   
    | 26 Spikes in more or less spherical 
      heads, appearing like one spike; high northern latitudes | 
    C. maritima  | 
  
   
    | 26 Spikes densely aggregated but not 
      in spherical heads, distinct; distribution various | 
    27  | 
  
   
    |   | 
     | 
  
   
    | 27 Perigynia wing-margined, beak with 
      two conspicuous teeth; terminal spike with female flowers above male flowers, 
      middle male flowers only, lower female flowers only | 
    C. siccata  | 
  
   
    | 27 Perigynia not wing-margined, beak 
      without two conspicuous teeth; spikes with male flowers above female flowers | 
    28  | 
  
   
    |   | 
     | 
  
   
    | 28 Upper leaf sheaths green; two darks 
      warts present at junction of leaf blade and sheath | 
    C. sartwellii  | 
  
   
    | 28 Upper leaf sheaths transparent 
      or brown; warts at junction of leaf blade and sheath absent | 
    C. duriuscula  | 
  
   
    |   | 
     | 
  
   
    | 29 Spikes with male flowers above 
      female flowers | 
    30  | 
  
   
    | 29 At least upper spikes with female 
      flowers above male flowers, lateral spikes may be female-flowered | 
    39  | 
  
   
    |   | 
     | 
  
   
    | 30 Spikes few-flowered, with 2 – 
      3 perigynia and 1 – 2 male flowers | 
    C. disperma  | 
  
   
    | 30 Spikes with numerous flowers | 
    31  | 
  
   
    |   | 
     | 
  
   
    | 31 Spikes 4 – 10, no more than 
      one spike per axis node; sheaths not red-dotted | 
    32  | 
  
   
    | 31 Spikes numerous, axis nodes may 
      have 2 or more spikes; sheath often red-dotted ventrally or copper-tinged | 
    35  | 
  
   
    |   | 
     | 
  
   
    | 32 Leaves < 2 mm wide; spikes widely 
      spaced, in linear arrangement; female flower scales short-awned | 
    C. hookerana  | 
  
   
    | 32 Leaves > 2 mm wide; spikes bunched 
      into round or ovoid arrangement; female flower scales not awned (may be 
      short awned in C. gravida) | 
    33  | 
  
   
    |   | 
     | 
  
   
    | 33 Arrangement of spikes spherical 
      or rounded; Cypress Hills | 
    C. hoodii  | 
  
   
    | 33 Arrangement of spikes ovoid, at 
      least 2 x as long as broad; southern Saskatchewan | 
    34  | 
  
   
    |   | 
     | 
  
   
    | 34 Stems markedly triangular, not 
      wing-margined | 
    C. gravida var. gravida  | 
  
   
    | 34 Stems becoming flattened in drying, 
      wing-margined | 
    C. alopecoidea  | 
  
   
    |   | 
     | 
  
   
    | 35 Sheaths loose; stems soft and spongy; 
      perigynia spongy and corky | 
    36  | 
  
   
    | 35 Sheaths tight; stems slender and 
      firm; perigynia firm | 
    37  | 
  
   
    |   | 
     | 
  
   
    | 36 Perigynia oval, at most only slightly 
      surpassing scales; leaves 2 – 6 mm wide | 
    C. alopecoidea  | 
  
   
    | 36 Perigynia triangular, surpassing 
      the scales; leaves 4 – 10 mm wide | 
    C. stipata var. stipata  | 
  
   
    |   | 
     | 
  
   
    | 37 Female flower scales awned; perigynia 
      yellowish or straw-coloured, blackish in age; leaf sheaths cross-wrinkled | 
    C. vulpinoidea var. vulpinoidea  | 
  
   
    | 37 Female flower scales tapered to 
      the tip; perigynia brownish or black; leaf sheaths not cross wrinkled | 
    38  | 
  
   
    |   | 
     | 
  
   
    | 38 Leaf sheath copper-tinged at summit; 
      perigynia brownish, convex on one side | 
    C. prairea  | 
  
   
    | 38 Leaf sheath red-dotted; perigynia 
      blackish, convex on both sides | 
    C. diandra  | 
  
   
    |   | 
     | 
  
   
    | 39 Perigynia narrowly or broadly winged, 
      not thickened at base; beak present, usually with two teeth; achene narrower 
      than perigynium | 
    40  | 
  
   
    | 39 Perigynia at most thin-edged, thickened 
      at base; beak, if present, with two teeth or not; achene more than half 
      as wide as perigynium | 
    45  | 
  
   
    |   | 
     | 
  
   
    | 40 Bracts leaf-like OR clearly surpassing 
      the spikes; spikes aggregated into a terminal head-like cluster | 
    41  | 
  
   
    | 40 Bracts not leaf-like, shorter than 
      spikes; spikes aggregated into lateral and terminal clusters | 
    42  | 
  
   
    |   | 
     | 
  
   
    | 41 Bracts leaf-like; female flower 
      scales greenish-white; stems smooth | 
    C. syncocephala  | 
  
   
    | 41 Bracts clearly surpassing the spikes 
      but not leaf-like; female flower scales reddish-brown and copper-margined; 
      stems roughened below the head | 
    C. athrostachya  | 
  
   
    |   | 
     | 
  
   
    | 42 Perigynia narrowly triangular, 
      < 1 mm wide | 
    C. crawfordii  | 
  
   
    | 42 Perigynia lance-shaped, elliptic, 
      oval, or round, > 1 mm wide | 
    43  | 
  
   
    |   | 
     | 
  
   
    | 43 Perigynia concealed by female flower 
      scales or nearly so | 
    44  | 
  
   
    | 43 Perigynia not concealed by narrower 
      or shorter female flower scales | 
    49  | 
  
   
    |   | 
     | 
  
   
    | 44 Perigynia beak flattened and markedly 
      saw-toothed to tip, two teeth present | 
    45  | 
  
   
    | 44 Perigynia beak nearly round, if 
      saw-toothed, only slightly so, two teeth not noticeably present | 
    48  | 
  
   
    |   | 
     | 
  
   
    | 45 Inflorescence like a string of 
      beads | 
    46  | 
  
   
    | 45 Inflorescence not like a string 
      of beads, spikes aggregated or approximate | 
    47  | 
  
   
    |   | 
     | 
  
   
    | 46 Female flower scales larger than 
      or equal to perigynia; leaf sheaths tight | 
    C. foena var. foena  | 
  
   
    | 46 Female flower scales smaller than 
      perigynia; leaf sheaths weak | 
    C. projecta  | 
  
   
    |   | 
     | 
  
   
    | 47 Scales pale or silvery, appressed; 
      spikes approximate | 
    C. xerantica  | 
  
   
    | 47 Scales brown, ascending; spikes 
      aggregated | 
    C. adusta  | 
  
   
    |   | 
     | 
  
   
    | 48 Perigynium 6 – 8 mm long, 
      widest near the middle | 
    C. petasata  | 
  
   
    | 48 Perigynium 4 – 6 mm long, 
      widest at the base | 
    C. pratincola  | 
  
   
    |   | 
     | 
  
   
    | 49 Perigynium narrowly lance-shaped | 
    C. scoparia  | 
  
   
    | 49 Perigynium oval, elliptic, or round | 
    50  | 
  
   
    |   | 
     | 
  
   
    | 50 Beak of perigynium round in cross 
      section and only slightly saw-toothed | 
    51  | 
  
   
    | 50 Beak of perigynium flattened and 
      saw-toothed to tip | 
    52  | 
  
   
    |   | 
     | 
  
   
    | 51 Perigynia reddish to dark coppery-brown | 
    C. pachystachya  | 
  
   
    | 51 Perigynia straw-coloured or light 
      green to brown | 
    C. microptera  | 
  
   
    |   | 
     | 
  
   
    | 52 Perigynium 4 – 6 mm long, 
      nearly round, leathery | 
    C. brevior  | 
  
   
    | 52 Perigynium 3 – 4 mm long, 
      oval, membranaceous | 
    53  | 
  
   
    |   | 
     | 
  
   
    | 53 Spikes distant, inflorescence like 
      a string of beads; perigynia straw-coloured at maturity; leaves 1 – 
      3 mm wide | 
    C. tenera  | 
  
   
    | 53 Spikes closely aggregated; perigynia 
      brown at maturity; leaves 2 – 6 mm wide | 
    54  | 
  
   
    |   | 
     | 
  
   
    | 54 Perigynia wing-margined to base; 
      leaves < 4 mm wide | 
    C. bebbii  | 
  
   
    | 54 Perigynia wing-margined, but reduced 
      at base; leaves > 4 mm wide | 
    C. cristatella  | 
  
   
    |   | 
     | 
  
   
    | 55 Perigynia thin-edged, not pitted 
      or gland-dotted, spreading or reflexed | 
    56  | 
  
   
    | 55 Perigynia with rounded margins, 
      pitted or gland dotted or not, ascending | 
    58  | 
  
   
    |   | 
     | 
  
   
    | 56 Perigynium beak < 1/3 overall 
      perigynium length; female flower scales shorter than perigynium body | 
    C. interior  | 
  
   
    | 56 Perigynium beak > 1/3 overall 
      perigynium length; female flower scales longer than perigynium body | 
    57  | 
  
   
    |   | 
     | 
  
   
    | 57 Perigynia obscurely nerved or nerveless 
      ventrally | 
    C. echinata  | 
  
   
    | 57 Perigynia lightly to strongly nerved 
      on both faces | 
    C. sterilis  | 
  
   
    |   | 
     | 
  
   
    | 58 Perigynia > 4 mm long, not pitted 
      or gland-dotted; beak long, with two teeth; achene occupying 1/2 to 1/3 
      or perigynium | 
    C. deweyana  | 
  
   
    | 58 Perigynia < 4 mm long, white-dotted; 
      beak short or absent; achene filling body or perigynium  | 
    59  | 
  
   
    |   | 
     | 
  
   
    | 59 Lowest bract exceeding inflorescence 
      by several times; spikes 1 – 5-flowered; perigynia 3 – 4 mm 
      long | 
    C. trisperma   | 
  
   
    | 59 Bracts absent or lowest bract shorter 
      than inflorescence; spikes several flowered; perigynia < 3 mm long | 
    60  | 
  
   
    |   | 
     | 
  
   
    | 60 Perigynia beakless; scales silvery 
      to white transparent; slender runners present | 
    61  | 
  
   
    | 60 Perigynia short-beaked; scales 
      greenish or brownish to straw-coloured or rusty; runners absent | 
    62  | 
  
   
    |   | 
     | 
  
   
    | 61 Spikes 2 – 4, aggregated; 
      perigynia faintly nerved | 
    C. tenuiflora  | 
  
   
    | 61 Spikes 3 – 5, remote; perigynia 
      strongly nerved or ribbed | 
    C. loliacea  | 
  
   
    |   | 
     | 
  
   
    | 62 Perigynia oval, beak saw-toothed; 
      spikes 6 – many | 
    C. arcta  | 
  
   
    | 62 Perigynia broadest near middle, 
      beak smooth to moderately saw-toothed; spikes 2 - 9 | 
    63  | 
  
   
    |   | 
     | 
  
   
    | 63 Spikes 3 – 4, spherical, 
      more or less overlapping; scales reddish | 
    C. heleonastes  | 
  
   
    | 63 Spikes 4 or more, cone-shaped or 
      ellipsoidal, inflorescence interrupted, only upper spikes overlapping if 
      at all; scales greenish to straw-coloured | 
    64  | 
  
   
    |   | 
     | 
  
   
    | 64 Plants green; spikes 5 – 
      15-flowered; woodland species | 
    C. brunnescens  | 
  
   
    | 64 Plants bluish-green; spikes 15 
      – 30-flowered; bog species | 
    C. canescens ssp. canescens  | 
  
   
    |   | 
     | 
  
   
    | 65 Perigynia beak markedly toothed, 
      teeth conspicuous, usually two | 
    66  | 
  
   
    | 65 Perigynia beakless or beaked, beak 
      if present, without conspicuous teeth | 
    86  | 
  
   
    |   | 
     | 
  
   
    | 66 Perigynia at least somewhat hairy; 
      style jointed with achene | 
    67  | 
  
   
    | 66 Perigynia hairless; style jointed 
      or continuous with achene | 
    76  | 
  
   
    |   | 
     | 
  
   
    | 67 Achenes with convex sides; lower 
      bracts shorter than or equal to inflorescence | 
    68  | 
  
   
    | 67 Achenes with flat sides; lower 
      bracts longer than inflorescence | 
    74  | 
  
   
    |   | 
     | 
  
   
    | 68 Hairs on perigynia reduced to one 
      line on each side of the two ribs | 
    C. tonsa var. tonsa  | 
  
   
    | 68 Perigynia distinctly hairy | 
    69  | 
  
   
    |   | 
     | 
  
   
    | 69 Female-flowered spikes all on the 
      stem; stems all elongate | 
    70  | 
  
   
    | 69 Some female-flowered spikes short-stalked 
      at the base of the plant; stems of various lengths | 
    72  | 
  
   
    |   | 
     | 
  
   
    | 70 Male-flowered spike 10 – 
      20 mm long; perigynium body spherical; scales about as long as perigynium; 
      dry prairies | 
    C. inops ssp. heliophila  | 
  
   
    | 70 Male-flowered spike 2 – 10 
      mm long; perigynium body ellipsoid to spindle-shaped to obovoid; scales 
      shorter than perigynium, usually about up to base of beak; woodlands | 
    71  | 
  
   
    |   | 
     | 
  
   
    | 71 Perigynia > 3 mm long; scales 
      with white sides; male-flowered spike 5 – 10 mm long; stems 15 – 
      30 cm tall | 
    C. peckii  | 
  
   
    | 71 Perigynia < 3 mm long; scales 
      with purple sides; male-flowered spike 2 – 5 mm long; stems 5 – 
      15 cm tall | 
    C. deflexa  | 
  
   
    |   | 
     | 
  
   
    | 72 Bracts of female-flowered spikes 
      on the stem poorly developed; remnants of old leaves stiff and shredded | 
    C. umbellata  | 
  
   
    | 72 Bracts of female-flowered spikes 
      on the stem well developed; remnants of old leaves soft and only slightly 
      shredded if at all | 
    73  | 
  
   
    |   | 
     | 
  
   
    | 73 Rhizomes slender; leaves soft and 
      thin; male-flowered spike 2 – 5 mm long, nearly stalkless | 
    C. deflexa  | 
  
   
    | 73 Rhizomes stout; leaves thin but 
      firm; male-flowered spike 3 – 15 mm long, stalked | 
    C. rossii  | 
  
   
    |   | 
     | 
  
   
    | 74 Stems 1 – 3; perigynia finely 
      hairy, 5 – 7 mm long, conspicuously nerved; dry habitats  | 
    C. houghtoniana  | 
  
   
    | 74 Stems many, bunched; perigynia 
      densely hairy, 3 – 5 mm long, nerves obscured by hairs; damp or aquatic 
      habitats | 
    75  | 
  
   
    |   | 
     | 
  
   
    | 75 Leaves thread-like or inrolled, 
      < 2 mm wide; old leaf sheaths persistent at base of stem  | 
    C. lasiocarpa var. americana  | 
  
   
    | 75 Leaves flat, 2 – 5 mm wide; 
      old leaf sheaths absent | 
    C. pellita  | 
  
   
    |   | 
     | 
  
   
    | 76 Style entirely deciduous from achene, 
      no part persistent; leaves without minute bumps  | 
    C. sprengellii  | 
  
   
    | 76 Style not withering to base, lower 
      part of style persisting as a “prong”; leaves usually with minute 
      bumps | 
    77  | 
  
   
    |   | 
     | 
  
   
    | 77 Perigynia narrowly triangular; 
      female-flowered spikes spherical; northern latitudes | 
    C. michauxiana  | 
  
   
    | 77 Perigynia lance-shaped to oval; 
      female-flowered spikes longer than broad; distribution varies | 
    78  | 
  
   
    |   | 
     | 
  
   
    | 78 Perigynia leathery, not shining; 
      scarcely inflated | 
    79  | 
  
   
    | 78 Perigynia membranous, thin, shining 
      or not; usually inflated | 
    82  | 
  
   
    |   | 
     | 
  
   
    | 79 Female flower scales with a short 
      narrow body and a long rough awn; wet woodland species | 
    C. pseudocyperus  | 
  
   
    | 79 Female flower scales tapered to 
      the tip, the body visible; large water sedges | 
    80  | 
  
   
    |   | 
     | 
  
   
    | 80 Leaves long-hairy beneath, sheaths 
      long-hairy; teeth or perigynium beak prominent, 1.5 – 3 mm long, divergent | 
    C. atherodes  | 
  
   
    | 80 Leaves and sheaths hairless; teeth 
      of perigynium beak short, < 1.5 mm long, nearly straight | 
    81  | 
  
   
    |   | 
     | 
  
   
    | 81 Perigynia teeth 1 – 1.5 mm 
      long; large sedge, stem 60 – 150 cm tall | 
    C. lacustris  | 
  
   
    | 81 Perigynia teeth < 1 mm long; 
      average-sized sedge, stem 30 – 80 cm tall | 
    C. laeviconica  | 
  
   
    |   | 
     | 
  
   
    | 82 Perigynia 12 – 25 nerved, 
      not shining | 
    C. hystericina  | 
  
   
    | 82 Perigynia 7 – 9 nerved, shining | 
    83  | 
  
   
    |   | 
     | 
  
   
    | 83 Lower perigynia reflexed; lower 
      bracts exceeding inflorescence by at least 2 x; spikes approximate | 
      C. retrorsa  | 
  
   
    | 83 Lower perigynia ascending to spreading; 
      lower bracts exceeding inflorescence, but by < 2 x; spikes often distant | 
    84  | 
  
   
    |   | 
     | 
  
   
    | 84 Rhizomes absent; perigynia ascending 
      at maturity, in 6 – 8 vertical rows | 
    C. vesicaria var. raeana  | 
  
   
    | 84 Rhizomes present; perigynia spreading 
      at maturity, in 8 – 12 or more vertical rows | 
    85  | 
  
   
    |   | 
     | 
  
   
    | 85 Stems 40 – 70 cm tall; leaves 
      2 – 6 mm wide; female spikes densely 50 – 125-flowered | 
    C. rostrata  | 
  
   
    | 85 Stems 50 – 80 cm tall; leaves 
      4 – 8 mm wide; female spikes densely 100 – 200-flowered | 
    C. utricularia  | 
  
   
    |   | 
     | 
  
   
    | 86 Perigynia more or less hairy | 
    87  | 
  
   
    | 86 Perigynia hairless | 
    95  | 
  
   
    |   | 
     | 
  
   
    | 87 Female spikes loosely flowered; 
      perigynia narrowly lance-shaped | 
    C. assiniboinensis  | 
  
   
    | 87 Female spikes densely flowered; 
      perigynia oval or elliptic | 
    88  | 
  
   
    |   | 
     | 
  
   
    | 88 Perigynia round in cross section; 
      female flower bracts sheathless | 
    89  | 
  
   
    | 88 Perigynia obtusely triangular; 
      female flower bracts long-sheathing | 
    93  | 
  
   
    |   | 
     | 
  
   
    | 89 Female-flowered spikes all on the 
      stem; stems all elongate | 
    90  | 
  
   
    | 89 Some female-flowered spikes short-stalked 
      at the base of the plant; stems of various lengths | 
    91  | 
  
   
    |   | 
     | 
  
   
    | 90 Perigynia > 3 mm long; scales 
      with white sides; male-flowered spike 5 – 10 mm long; stems 15 – 
      30 cm tall | 
    C. peckii  | 
  
   
    | 90 Perigynia < 3 mm long; scales 
      with purple sides; male-flowered spike 2 – 5 mm long; stems 5 – 
      15 cm tall | 
    C. deflexa  | 
  
   
    |   | 
     | 
  
   
    | 91 Bracts of female-flowered spikes 
      on the stem poorly developed; remnants of old leaves stiff and shredded | 
    C. umbellata  | 
  
   
    | 91 Bracts of female-flowered spikes 
      on the stem well developed; remnants of old leaves soft and only slightly 
      shredded if at all | 
    92  | 
  
   
    |   | 
     | 
  
   
    | 92 Rhizomes slender; leaves soft and 
      thin; male-flowered spike 2 – 5 mm long, nearly stalkless | 
    C. deflexa  | 
  
   
    | 92 Rhizomes stout; leaves thin but 
      firm; male-flowered spike 3 – 15 mm long, stalked | 
    C. rossii  | 
  
   
    |   | 
     | 
  
   
    | 93 Terminal spike with male flowers 
      above female flowers, lower spikes on long hair-like stalks; female flower 
      scales awned | 
    C. pedunculata  | 
  
   
    | 93 Terminal spike male-flowered, lower 
      (female-flowered) spikes stalkless or short-stalked; female flower scales 
      blunt-tipped | 
    94  | 
  
   
    |   | 
     | 
  
   
    | 94 Male-flowered spike < 6 mm long, 
      stalkless; perigynia 2-ribbed with several nerves; stigma short | 
    C. cocinna  | 
  
   
    | 94 Male-flowered spike to 2 cm long, 
      short-stalked; perigynia 2-ribbed but otherwise nerveless; stigma long | 
    C. richardsonii  | 
  
   
    |   | 
     | 
  
   
    | 95 Leaves and sheaths hairy; perigynia 
      hairless but appearing felty and conspicuously 15 – 25-nerved | 
    C. torreyi  | 
  
   
    | 95 Leaves and sheaths hairless; perigynia 
      otherwise | 
    96  | 
  
   
    |   | 
     | 
  
   
    | 96 Leaf sheath > 3 mm long | 
    97  | 
  
   
    | 96 Leaf sheath < 3 mm long or sheathless | 
    105  | 
  
   
    |   | 
     | 
  
   
    | 97 Leaves thread-like; bracts bladeless 
      but sheathing | 
    C. eburnea  | 
  
   
    | 97 Leaves > 0.5 mm wide; bracts 
      with well developed blades | 
    98  | 
  
   
    |   | 
     | 
  
   
    | 98 Female-flowered spikes elongate, 
      < 4 mm wide, on hair-like stalks; plants tufted | 
    C. capillaries  | 
  
   
    | 98 Female-flowered spikes short, > 
      4 mm wide, on short stalks; plants tufted or rhizomatous | 
    99  | 
  
   
    |   | 
     | 
  
   
    | 99 Plants tufted; perigynia conspicuously 
      nerved | 
    100  | 
  
   
    | 99 Plants rhizomatous; perigynia obscurely 
      nerved, if at all | 
    102  | 
  
   
    |   | 
     | 
  
   
    | 100 Spikes nearly stalkless, closely 
      bunched; perigynia 6 – 14-nerved | 
    C. viridula ssp. viridula  | 
  
   
    | 100 Spikes stalked, the lower distant; 
      perigynia 15 – 30-nerved | 
    101  | 
  
   
    |   | 
     | 
  
   
    | 101 Perigynia sharply triangular, 
      narrowed at base to stalk; beak at right angles to perigynia | 
    C. leptonervia  | 
  
   
    | 101 Perigynia nearly round, rounded 
      at base; stalk absent; beak straight, very small | 
    C. granularis var. haleana  | 
  
   
    |   | 
     | 
  
   
    | 102 Perigynium body widest below middle, 
      rounded at base | 
    C. crawei  | 
  
   
    | 102 Perigynium body widest at or above 
      middle and tapering to acute base | 
    103  | 
  
   
    |   | 
     | 
  
   
    | 103 Perigynia beaked, beak toothless; 
      leaves deep green | 
    C. vaginata  | 
  
   
    | 103 Perigynia beakless; leaves bluish-green 
      or gray-green | 
    104  | 
  
   
    |   | 
     | 
  
   
    | 104 Leaves bluish-green, < 3.5 
      mm wide, soon folded or inrolled; northern bog species | 
    C. livida  | 
  
   
    | 104 Leaves gray-green, 2 – 5 
      mm wide, flat; prairies | 
    C. tetanica  | 
  
   
    |   | 
     | 
  
   
    | 105 Perigynia inflated and shiny; 
      female-flowered spikes sessile, globular | 
    106  | 
  
   
    | 105 Perigynia not both inflated and 
      shiny; female-flowered spikes nearly stalkless to stalked, elongate | 
    107  | 
  
   
    |   | 
     | 
  
   
    | 106 Perigynia ~ 7 mm long; style not 
      withering at maturity; plant 50 – 80 cm tall | 
    C. oligosperma  | 
  
   
    | 106 Perigynia 2 – 4 mm long; 
      style withering at maturity; plant 5 – 20 cm tall | 
    C. supina var. spaniocarpa  | 
  
   
    |   | 
     | 
  
   
    | 107 Perigynia conspicuously many nerved | 
    108  | 
  
   
    | 107 Perigynia obscurely nerved, may 
      have 2 conspicuous marginal nerves | 
    113  | 
  
   
    |   | 
     | 
  
   
    | 108 Perigynia spreading to reflexed | 
    C. cryptolepis  | 
  
   
    | 108 Perigynia ascending to appressed | 
    109  | 
  
   
    |   | 
     | 
  
   
    | 109 Stems lateral, previous year’s 
      leaves on separate shoots | 
    C. buxbaumii  | 
  
   
    | 109 Stems central, surrounded by persistent 
      leaves of preceding year’s growth | 
    110  | 
  
   
    |   | 
     | 
  
   
    | 110 Stem leaves absent or only a few 
      towards base of stem; perigynia 1.5 – 2.5 mm long; female flower scales 
      1.5 – 2.5 mm long | 
    111  | 
  
   
    | 110 Stems leaves on lower 1/4 of stem; 
      perigynia 3 – 4.5 mm long; female flower scales > 2.5 mm long | 
    112  | 
  
   
    |   | 
     | 
  
   
    | 111 Scales as long as perigynia, brownish; 
      stems obtusely triangular | 
    C. parryana var. parryana  | 
  
   
    | 111 Scales much shorter than perigynia, 
      purplish; stem sharply triangular | 
    C. norvegica ssp. inferalpina  | 
  
   
    |   | 
     | 
  
   
    | 112 Perigynia almost circular, little 
      pitted or gland-dotted; terminal spike male-flowered; Cypress Hills | 
    C. raynoldsii  | 
  
   
    | 112 Perigynia flattened, markedly 
      pitted; terminal spike with female flowers above male flowers; northern 
      mixed wood forest | 
    C. raymondii  | 
  
   
    |   | 
     | 
  
   
    | 113 Perigynia nearly round; achenes 
      smooth surfaced | 
    C. glacialis  | 
  
   
    | 113 Perigynia flat-triangular to lens-shaped; 
      achenes with bumps | 
    114  | 
  
   
    |   | 
     | 
  
   
    | 114 Rootlets with yellow fuzz; terminal 
      spike male-flowered | 
    115  | 
  
   
    | 114 Rootlets without yellow fuzz; 
      terminal spike with female flowers above male | 
    116  | 
  
   
    |   | 
     | 
  
   
    | 115 Female flower scales long tapered; 
      male spike 4 – 12 mm; leaves to 3 mm broad, flat  | 
    C. magellanica ssp. irrigua  | 
  
   
    | 115 Female flower scales short tapered; 
      male spike 10 – 30 mm; leaves less than or equal to 3 mm broad, somewhat 
      inrolled | 
    C. limosa  | 
  
   
    |   | 
     | 
  
   
    | 116 Stems lateral, previous year’s 
      leaves on separate shoots | 
    C. buxbaumii  | 
  
   
    | 116 Stems central, surrounded by persistent 
      leaves from preceding years | 
    C. norvegica ssp. inferalpina  |