Definition of plume poppy in US English:

plume poppy

noun

  • Either of two tall poppies of the east Asian genus Macleaya, M. cordata and M. microcarpa, which have large lobed cordate leaves and plume-like panicles of small cream or pink flowers; also called bocconia, macleaya.

Origin

Late 19th century; earliest use found in William Robinson (1838–1935), horticulturist and publisher.