I would guess a cultivar of Hollyhock. Is it growing on an upright stem? The leaf is a little different than the Hollyhock's I'm familiar with but there are some cultivars with similar leaves.
Look up purple malva, it's a close relative of the hollyhock and in the mallow family. One of the big differences between the two is that holllyhock has tall stallks. Malve is shorter and can be more bush like with tall stalks. The leaf structures are similar as well. The bonus with malva is that the flowers and leaves are edible and safe.