Birch
classification
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Birch is the name of any
tree of the genus
Betula, in the family
Betulaceae, closely related to the
beech/
oak family,
Fagaceae. These are generally small to medium-size
trees or
shrubs, mostly of northern
temperate climates. The simple
leaves may be toothed or lobed. The fruit is a small
samara, although the wings may be obscure in some species. They differ from the
alders (
Alnus, the other genus in the family) in that the female catkins are not woody and disintegrate at maturity, falling apart to release the seeds, unlike the woody cone-like female alder catkins.
In times past, commercial oil of wintergreen (
methyl salicylate) was made from the sweet birch (
Betula lenta).
Birches of
North America include:
- Betula allegheniensis - Yellow birch (B. lutea)
- Betula cordifolia - Mountain paper birch
- Betula glandulosa - American dwarf birch
- Betula lenta - Sweet birch or Cherry birch
- Betula lenta subsp. uber - Cherry Creek birch (endemic, Cherry Creek, Smythe Co., VA)
- Betula michauxii - Newfoundland dwarf birch
- Betula neoalaskana - Alaska birch or Yukon birch
- Betula nigra - River birch or Black birch
- Betula occidentalis - Water birch or Red birch (B. fontinalis)
- Betula papyrifera - Paper birch, Canoe birch or White birch
- Betula populifolia - Gray birch
- Betula pumila - Swamp birch
European and
South West Asian birches include:
- Betula medwediewii - Caucasian birch
- Betula nana - Dwarf birch (also in Asia)
- Betula pendula - Silver birch
- Betula pubescens - White birch, European white birch or Downy birch (also in northern Asia)
- Betula pubescens subsp. tortuosa - Arctic white birch (subarctic Eurasia, Greenland)
- Many American texts appear to have B. pendula and B. pubescens confused, though they are distinct species with different chromosome numbers
Asian birches include:
- Betula albosinensis - Chinese red birch
- Betula albosinensis var. septentrionalis - North Chinese red birch
- Betula alnoides - Alder-leaf birch
- Betula austrosinensis - South China birch
- Betula chinensis - Chinese dwarf birch
- Betula ermanii - Erman's birch
- Betula grossa - Japanese cherry birch
- B. jacquemontii (Betula utilis subsp. jacquemontii) - White-barked Himalayan birch
- Betula mandschurica - Manchurian birch
- Betula mandschurica var. japonica - Japanese birch
- Betula maximowiczii - Monarch birch
- Betula platyphylla (Betula pendula var. platyphylla) - Siberian silver birch
- Betula szechuanica (Betula pendula var. szechuanica) - Sichuan birch
- Betula utilis - Himalayan birch
See also
