Key

• Key A -- Gills and/or flesh initially yellow, green or olivaceous
  • Cap ± hygrophanus, often bicolored, or with dark, hygrophanus spots; pileipellis duplex, with a ± cellular hypoderm, smell honeylike, sp.ellipsoid
    C.scaurus, C.herpeticus
  • Cap not hygrophanus, pileipellis simplex, without a hypoderm, sp. amygdaloid-citriniform
    • Smell strong and sweet like H.sacchariolens, also with a component of black pepper when bruise/cut
      C.odoratus
    • Smell faint, weak malty, farinaceous,like black pepper, boiled potatoes, anis, radish, unripe banana, apple, marjoram or lemon cake
      • KOH on cap distinctly red, purplish red to purplish brown or blackish
        • Smell like black pepper
          C.atrovirens, C.ionochlorus
        • Smell faint, weak malty, like boiled potatoes or anis
          • Gills, cap, stem, flesh initially yellow without greenish yellow or olivaceous tinges, cap red with KOH and still red after 15 mn, exsiccates not vinaceous or purplish
            C.olearioides, C.alcalinophilus
          • Gills, cap, stem or flesh initially with greenish yellow or olivaceous tinges, cap purplish brown, greenish or red and then becoming dark purplish red to ± blackish after 15 mn, exsiccates usually distingly vinaceous or purplish
            • Smell distinct of anis
              C.odorifer
            • Smell not of anis
              • Cap margin on young ex. greenish yellow
                C.elegantissimus, C.prasinus, C.caesiolatens, C.aureofulvus, C.cedretorum
              • Cap margin on young ex. green, olivaceous or ±violaceous
                • with conifers
                  C.cupreorufus
                • with deciduous trees, thermophilous
                  C.rufoolivaceus, C.xanthophyllus, C.splendificus, C.glaucescens, C.prasinus
      • KOH on cap negative, brownish to ± red brown, or weakly olivaceous
        • Young gills brown, flesh brown in stem top, otherwise greenish yellow
          C.fulvocitrinus
        • Young gills greenish yellow, flesh in stem top not brownish when young
          • Flesh in both bulb and cap bright yellow or greenish yellow, ex. intensely colored
            C.meinhardii, C.citrinus, C.splendens
          • Flesh at least in the cap less bright colored, ex. intensely colored or not
            • KOH in bulb flesh rose to reddish
              C.elegantior, C.majoranae, C.xanthosuavis, C.bulbopodius, C.auricilis
            • KOH in bulb flesh negative
              • Smell and taste distinctly farinaceous or radish/earthy
                C.flavovirens, C.humolens, C.osloensis
              • Smell and taste indistinct, slightly malty or parseylike
                C.sulfurinus, C.natalis, C.quercilis, C.xanthochlorus
• Gills and/or flesh whitish, violaceous, brownish, cream or ochraceous, not yellow, green or olivaceous
  • Key B -- Cap cuticle violaceous or blue, at least at margin
    • Pileipellis duplex, bulbipellis not distinctly pink on with KOH, sp. distinctly verrucose with isolated warts, cap often innately radially fibrillose
      • Sp. ellipsoid
        C.eucaeruleus, C.terpsichores
      • Sp. amygdaloid or citriform
        C.moënne-loccozii, C.caerulescens, C.lepistoides, C.caesiocanescens, C.aurantiobasalis
    • Pileipellis simplex, bulbipellis in most species distinctly pink with KOH, sp. coarsely verucose with irregular warts, cap rarely distinctly radially fibrillose
      • KOH on bulbipellis negative
        C.suaveolens, C.lilacinovelatus, C.ionodactylus, C.vesterholtii
      • KOH on bulbipellis distinctly pink
        • KOH in flesh distinctly pink, gill edge ± sterile with conspicious sterile elements
          C.dibaphus
        • KOH in flesh negative to greyish rose, gill edge ± fertile without conspicious sterile elements
          • KOH on cap weakly rose, cap predominantly cream to ochraceous, usually only with a weak pinkish tinge or only sligtly bluish at margin, with frondose trees, microchemical pileipellis reaction pink in a few isolated areas, with abondant extracellular crystals
            C.selandicus
          • KOH on cap usually distinctly pink to red, at least on blue areas of cap, cap usually with more distinct blue or grey to violaceus grey colours at least at margin, with frondose or coniferous trees, microchemical pileipellis reactions without pink colours or distinctly and predominantly pink
            • with conifers
              C.spectrabilis, caesiocinctus
            • with deciduous trees
              C.cordata, C.violaceipes, C.molochinus, C.sodagnitus, C.nymphicolor
  • Cap cuticle initially without violaceous or blue colors, but sometimes with violaceous veil remnants
    • Key C -- Gills initially with violaceous or blue color and/or bulbipellis pink with KOH
      • Bulbipellis or flesh distinctly pinkish with KOH, or universal veil on bulb edge with a red to a deep red-brown reaction with KOH, sp. on av. > 9 μ long
        
        • Flesh distictly pink with KOH, gill edge ± sterile with conspicious elements
          C.arcuatorum
        • Flesh not distinctly pink with KOH, but may be greyish rose, gill edge ± fertile, without conspicious elements
          • Cap whitish, cream or pale olivaceous, at least towards margin
            C.subgracilis, C.insignibulbus, C.selandicus, C.albertii, C.catharinae
          • Cap more lively coloured or darker brownish
            • Cap brown, olivaceous brown to greyish, without yellow tinges
              C.aureocalceolatus, C.caesiocinctus, C.cordata, C.violaceipes
            • Cap yellow, olivaceous or yellow brown
              • Sp. (11.5)12-14 x 7-8.5 μ with conifers
                C. aureopulverulentus, C.barbaricus
              • Sp. 9.5-11.5(12) x 5.5-7.5 μ with deciduous trees or conifers
                C.cisticola, C.kristinae, C.catharinae, C.barbarorum
      • Bulbipellis and flesh not distinctly pink with KOH, KOH negative to brownish on universal veil or bulb edge, sp. on av. < 9 μ long or longer (?!)
        • Cap cuticle bitter, smell sweetish plum- to celerylike and often earthy
          C. anserinus
        • Cap cuticule mild or bitter, smell not sweetish plum- or celerylike
          • Sp. subglobose Q < 1.3
            C. prasinocyaneus
          • Sp. ellipsoid, amygdaloid or citriform, Q > 1.3
            • Pileipellis simplex without a (sub)cellular hypoderm, sp. with a coarse ornamentation of irregular ±interconnected warts and crusts, cap rarely innately fibriose, not hygrophanous, smell often slightly earthly
              • Mycelium strands and/or bulbipellis sulphur to lemon yellow
                C.calochrous, C.haasii
              • Mycelium strands and bulbipellis whitish, pale ochraceous or violaceous
                C.vesterholtii, C.piceae, C.lilacinovelatus, C.platypus
            • Pileipellis duplex, with a distinct (sub)cellular hypoderm, sp.with regular, isolated warts, cap ±innately fibrillose or hygrophaneous, smell ±maltlike
              
              • Cap cream to pale ochraceous
                C.coerulescentium, C.anomaloochrascens, C.foetens, C. caesiostramineus
              • Cap darker
                • Gills and stem becoming violaceous lilac when bruised
                  C.purpurascens, C.subpurpurascens
                • Gills and stem not becoming violaceous lilac when bruised
                  • Sp. on av. < 8.5 μ
                    C.magicus, C.glaucopus, C.pansa
                  • Sp. on av. > 8.5 μ
                    • Sp. on av. > 11 μ, ellipsoid,bulb rounded
                      C.riederi, C.argenteolilacinus
                    • Sp. on av. < 11μ, citriform to amygdaloid, bulb marginated
                      • Taste and smell distinctly farinaceous
                        C.dionysae
                      • Taste and smell not farinaceous
                        C.multiformium, C.viridocoeruleus, C.camptoros, C.luhmanii, C.arcifolius
    • Key D -- Gills initially with whitish, cream or ochraceous colours, bulbipellis unchanging to brownish with KOH, not distinctly pink
      • Basal mycelium or universal veil at stem base whitish at first, becoming rose when exposed, sp. < 8.5 μ
        C. turmalis, C.variegatus
      • Basal mycelium universal veil at stem base not becoming rose when exposed, sp. > 8.5 μ and/or distinctly ornamented and/or not very pale
        • Stem, bulb margin or flesh with violaceous to greyish blue tinges, at least when young
          • Pileipellis duplex
            C. sphagnophilus, C.coerulescentium, C.anomaloochrascens, C.foetens, C. caesiostramineus
          • Pileipellis simplex
            C. lilacinovelatus, C.caroviolaceus, C.flavidolilacinus, C.pseudoglaucopus, C.pseudoarcuatorum
        • Stem, bulb margin and flesh without violaceous to greyish blue tinges
          • Cap whitish, cream, pale ochraceous or pale grey brown
            • Sp. on av. <7.5 μ, ellipsoid and very pale, in dry Pinus forests, less often with Picea
              C. leucophanes
            • Sp. on av. > 7.5 μ, ellipsoid or not, cinnamon brown, with coniferous or deciduous trees
              • KOH in flesh ± yellow, with Pinus, more rarely Picea, on acid, sandy soil
                C.pinophilus, C.areni-silvae
              • KOH in flesh not yellow, with deciduous or coniferous trees, on acid, sandy soil or not
                • Smell and taste distinctly farinaceous
                  C. aleuriosmus
                • Smell and taste not farinaceous
                  • Pileipellis simplex
                    C.osmophorus, C.rapaceotomentosus, C.corrosus, C.carioviolaceus
                  • Pileipellis duplex
                    C.coerulescentium, C.anomaloochrascens, C.foetens, C.caesiostamineus
          • Cap yellow, yellow brown, orange brown to brown
            • With Conifers
              • KOH in flesh ± yellow, cap almost dry, with Pinus,on acid, sandy soil
                C.pinophilus, C.areni-silvae
              • KOH in flesh not yellow, cap distinctly viscid, with Pinus or not, on acid, sandy soil
                
                • in May-June
                  C.inexspectatus
                • in ultimo July to October
                  C.multiformis, C.napus, C.corrosus, C.piceae, C.dalecarlicus
            • With deciduous trees
              • Sp. subglobose
                C.caesiocortinatus
              • Sp. ellipsoid, amygdaloid to citriform
                • Bulbipellis greenish yellow to sulfur yellow, cap distinctly red to brown with KOH
                  C.langeorum
                • Bulbipellis whitish, KOH on cap negative ou indistinctly brownish
                  • Cap 70-120 (140)mm, with thick, concentric whitish to ochraceous brown velar patches
                    C.saporatus
                  • Cap 15-100 mm, without concentric whitish to ochraceous brown velar patches, pileipellis simplex or duplex
                    • Sp. citriform to slightly amygdaloid
                      C.multiformium, C.luteomarginatus, C.gracilor
                    • Sp. ellipsoid to amygdaloid
                      C.xanthoochraceus, C.talus, C.cliduchus, C.aquilanus