Common name: Mallow, French Hollyhock 'Bibor Felho'
Species sylvestris var. mauritiana
Plant Link: http://plantsdatabase.com/go/51465/
I have something very similar and it seeds all over, even out in the gravel barnyard.
Thanks! They have really been putting on a big show. monsky, this one is in full sun, but would probably grow well with at least half day of sun or light, filtered shade.