It is subdivided into a number of floristic provinces. Their delineation is debatable. According to a version of Takhtajan's classification, these are the Arctic, Atlantic European, Central European, Illyrian, Euxinian, Caucasian, Eastern European, Northern European, West Siberian, Altai-Sayan, Central Siberian, Transbaikalian, Northeastern Siberian, Okhotsk-Kamtchatkan and Canadian Provinces.
Caucasian Province (parts of Russia, Georgia, Armenia and Azerbaijan), with five endemic genera (Pseudovesicaria, Symphyoloma, Pseudobetckea, Trigonocaryum and Cladochaeta) and many endemic species (e.g. Betula raddeana, Papaver oreophilum, Corydalis pallidiflora, Сorydalis emanuelii, Cerastium kasbek, Сerastium argenteum, Сerastium multiflorum, Minuartia inamoena, Silena lacera, Gypsophila acutifolia, Dianthus fragrans, Sobolevskia caucasica, Draba bryoides, Draba elisabethae, Draba supranivalis, Draba molissima, Draba ossetica, Primula bayernii, Saxifraga subverticillata, Sedum stevenianum, Geranium renardii, Oxytropis owerinii, Genliana grossheimii, Gentinana septemfida var. lagodechiana, Gentiana marcowiczii, Veronica caucasica, Campanula andina, Centaurea amblyolepis, Lilium monadelphum, Galanthus latifolius, Ornithogalum magnum, Colchicum laetum, Asphodoline tenuior, Gagea helenae, Calamagrostis caucasica), many endemic species and genera shared with the Euxinian Province (e.g. Agasyllis, Sredinskya, Rhododendron caucasicum, Vaccinium arctostaphylos, Daphne pontica, Paris incompleta).
Eastern European Province (parts of Estonia, Latvia, Lithuania, Russia, Belarus, Ukraine, Moldova and Romania) without endemic genera, with some endemic species (e.g. Anemone uralensis, Papaver maeoticum, Dianthus eugeniae, Dianthus krylovianus, Dianthus volgicus, Diplotaxis cretacea, Sisymbrium wolgense, Syrenia talievii, Pyrus rossica, Hedysarum cretaceum, Нedysarum ucrainicum, Erodium beketowii, Linaria cretacea, Linaria macroura, Scrophularia cretacea)
Northern European Province (parts of Finland, Sweden, Norway and Russia), without endemic genera, with but few endemic species (e.g. Corispermum algidum, Castilleja schrenkii)
West Siberian Province (parts of Russia and Kazakhstan), without endemic genera, with few endemic species
Altai-Sayan Province (Parts of Russia and Mongolia), with one endemic genus (Microstigma) and many endemic species (e.g. Callianthemum sajanense, Eranthis sibirica, Aquilegia borodinii, Delphinium mirabile, Delphinium inconspicuum, Aconitum krylovii, Aconitum altaicum, Anemone baicalensis, Ranunculus sajanensis, Gymnospermium altaicum, Betula kelleriana, Stellaria martjanovii, Stellaria imbricata, Stellaria irrigua, Silene turgida, Aphragmus involucratus, Erysimum inense, Euphorbia alpina, Euphorbia altaica, Euphorbia tshuiensis, Rhodiola algida, Sedum populifolium, Chrysosplenium filipes, Caragana altaica, Vicia lilacina, Lathyrus frolovii, Lathyrus krylovii, Linum violascens, Scrophularia altaica, Schizonepeta annua, Valeriana petrophila, Brachanthemum baranovii, Echinops humilis, Saussurea serratuloides, Saussurea sajanensis, Allium pumilum, Carex tatjanae, species of Astragalus and Oxytropis)
Central Siberian Province (parts of Russia) without endemic genera, with but few endemic species
Transbaikalian Province (Parts of Russia and Mongolia) without endemic genera, with some endemic species (e.g. Aconitum montibaicalensis, Draba baicalensis, Saxifraga algisii, Potentilla adenotricha, Astragalus trigonocarpus, Oxytropis heterotricha, Mertensia serrulata)
Northeastern Siberian Province (parts of Russia), with one endemic genus (Gorodkovia) and many endemic species (e.g. Corydalis gorodkovii, Androsace gorodkovii, Saxifraga anadyrensis, Potentilla anadyrensis, Potentilla tollii, Helictotrichon krylovii, Poa lanatiflora).
Okhotsk-Kamchatkan Province (parts of Russia), with one endemic genus (Redowskia) and many endemic species (e.g. Abies gracilis, Picea kamtschatkensis, Delphinium ochotense, Aconitum ajanense, Aconitum ochotense, Corydalis redowskii, Stellaria peduncularis, Arenaria redowskii, Lychnis ajanensis, Sorbus kamtschatcensis, Oxytropis ajanensis, Oxytropis tilingii, Sambucus kamtschatica).