Fagus sylvatica, European beech, is the one we have here, in Swedish it's called en bok (with the plural flera bokar). http://en.wikipedia.org/wiki/Fagus_sylvatica

It is sometimes claimed that the word bokstav ('letter', as in A, B, C… ) is derived from this word, stav is a cognate of staff or stave, they would carve runes into oblong pieces of (often beech-) wood.

Funny, I heard "skanderna" lol

This happens with rather many words, especially when the "a" is followed by an "n". You have to learn it.