It looks to me as C. 'Black Runner', but i am not sure. it grew from a small plant with 3 leaves into a 6 foot monster in 4 months - half a day of sun, noon to sundown. Leaves in full sun are purple, younger shaded leaves are green with purple veining. It's running above ground stolons.
and it has some kind of special veining too clearly visible on some leaves on the underside and when it is back-lit and especially on the old yellowing leaf.
here are the pics. i got the flower too!
