There are a few dozen species all told,
distributed all over the temperate and arctic zones of the northern hemisphere;
the exact number is difficult to establish since they hybridise a lot. Most of
them look almost indistinguishable to a non-botanist (except, of
course, for the dwarf birches of the tundra, which are tiny shrubs), and
their common features include the characteristic silver-white or greyish-white
bark. The differences between, say, the American silver birch (which
reaches South America and crosses the equator there) and the European white
birch are very subtle indeed. The distrbution of the genus is (and has for a
long time been) too wide to be of any use in the Urheimat dispute.
Piotr
----- Original Message -----
Sent: Wednesday, October 25, 2000 3:57 PM
Subject: Re: [tied] PIE mustelids and seals
But, how many species of birch exist? What's their
geographical distribution, past and present?