Acanthus mollis, family Acanthaceae

Large, deeply lobed leaves. Tubular, mint-like flowers, white, pinkish or purple.

Native of S. Europe; cultivated in gardens US and UK.

The leaves of this plant are generally considered by historians to have been the
design inspiration for the Corinthian column capitals of Roman architecture (Wikipedia).

Grows to six feet by parking lot at Wunderlich County Park.