pentamerous

adjective

pen·​tam·​er·​ous pen-ˈta-mə-rəs 

: divided into or consisting of five parts

specifically : having each floral whorl consisting of five or a multiple of five members

Word History

Etymology

New Latin pentamerus, from penta- (from Greek) + -merus -merous

First Known Use

1821, in the meaning defined above