http://cards.webshots.com/cp-9933098...43915986jGrvsy

That link leads to some pictures of a plant that came with my house. I can't
identify it. Leaves look like carrot or parsley or even a fern (sort of),
stem growth habit is similar to fennel. The plant remained lively through
the entire winter, surrounded by snow, in temps down to zero. But, it seems
like a tender plant that should not have survived under those conditions.
It's now 4 feet tall. What is it???