On Tue, 19 Jun 2012 07:19:03 +0000, skippysje wrote:

Is this a weed?

Sonchus arvensis, field sowthistle, from the looks of it in the photos.
Are there rhizomes?

As to whether it's a weed or not... most people do consider it a weed, but
if you've got finches and other seed eaters around, they consider it a
great delicacy.

Kay