Bocconia frutescens with its inflorescence of single seeded fruit, one of the ‘woody’ Poppies that comprise the genus.  Macleaya cordata, from the same family, has a similar look, though topping out at around 8′ and is herbaceous in habit dying to the ground each winter.  Another Wiki picture of Bocconia f.  growing in Hawaii’ where it has escaped cultivation and threatens the few remaining native landscapes, particularly historically dry and mesic forests.