Bark on twigs rich in methyl salicylate (oil of wintergreen). Female catkins erect.
Diploid (2n = 28).Betula lenta - Sweet Birch or Cherry BirchBetula lenta subsp. uber - Cherry Creek BirchHexaploid (6n = 84).Betula allegheniensis - Yellow Birch (B. lutea)Decaploid (10n = 140).Betula austrosinensis - South China BirchBetula globispica -Betula insignis -Betula medwediewii - Caucasian BirchDuodecaploid (12n = 168).Betula megrelica -chromosome number not reportedBetula corylifolia - Hazel-leaf BirchBetula grossa - Japanese Cherry BirchBetula insignis -Bark on twigs contains some methyl salicylate. Female catkins pendulous.
Betula alnoides - Alder-leaf BirchBetula alnoides subsp. luminifera -Betula maximowiczii - Monarch BirchBark on twigs without methyl salicylate. Female catkins erect.
Diploid (2n = 28).Betula calcicola -Betula chichibuenis -Betula costata - Korean birchBetula nigra - River Birch or Black BirchBetula potaninii - Potanin's BirchTetraploid (4n = 56).Betula albosinensis - Chinese Red BirchBetula albosinensis var. septentrionalis - North Chinese Red BirchBetula ermanii - Erman's BirchBetula jacquemontii (B. utilis subsp. jacquemontii) - White-barked Himalayan BirchBetula utilis - Himalayan BirchHexaploid (6n = 84).Betula dahurica - Dahurian BirchBetula delavayi - Delavay's BirchBetula raddeana - Radde's BirchOctoploid (8n = 112).Betula chinensis - Chinese Birchchromosome number not reportedBetula fargesii - Farges's BirchBetula schmidtii - Schmidt's Birchchromosome number unknownBetula leopoldae Bark on twigs without methyl salicylate. Female catkins pendulous.
Diploid (2n = 28).Betula cordifolia - Heart-leaf Birch or Mountain Paper BirchBetula pendula - Silver BirchBetula mandschurica - Manchurian BirchBetula mandschurica var. japonica - Japanese BirchBetula neoalaskana - Alaska Birch or Yukon BirchBetula occidentalis - Water Birch or Red Birch (B. fontinalis)Betula platyphylla (Betula pendula var. platyphylla) - Siberian Silver BirchBetula populifolia - Gray BirchBetula szechuanica (Betula pendula var. szechuanica) - Sichuan BirchTetraploid (4n = 56).Betula celtiberica - Iberian White BirchBetula pubescens - White Birch, European White Birch or Downy BirchBetula pubescens subsp. tortuosa - Arctic White BirchPentaploid (5n = 70).Betula kenaica - Kenai BirchHexaploid (6n = 84).Betula papyrifera - Paper Birch, Canoe Birch or American White Birch (sometimes tetraploid or pentaploid)Small shrubs with small rounded leaves. Female catkins pendulous.
Diploid (2n = 28).Betula glandulosa (B. nana subsp. glandulosa) - American Dwarf BirchBetula nana - Dwarf BirchTetraploid (4n = 56).Betula minor - Quebec Dwarf BirchBetula pumila - Swamp Birchchromosome number not reportedBetula fruticosa -Betula hallii - Cascades Dwarf BirchBetula humilis - Arctic Dwarf BirchBetula michauxii - Newfoundland Dwarf BirchBetula microphylla -Betula middendorffii -