Kórnik: Botanical garden

It was already spring in Poland, though we still get lots of snow in Sapporo (that is by the way much farther south than Poland is).

Outside the Kórnik castle there is a huge botanical garden that we took a quick stroll in.

The strange knobs on the ground to the right of this tree are parts of the roots of the tree.

We saw some frogs mating.

My professor thinks all trees in Europe looks like this, and wondered why. We were told the ball shaped things are a parasite that lives in some trees (and I have never seen something like this in Sweden, so not "all trees in Europe").