Sets of Four

Acacia is an attractive, rarely used Greek flower name enhanced by its popular beginning-and-ending-with 'a'-construct, and is gradually beginning to catch on as a new member of the stylish girl names starting with A.

Bryony is an unusually strong plant name --the bryony is a wild climbing vine with green flowers --that caught on in the U.K. before sprouting here. The name of the young character in the Ian McEwan novel Atonement is spelled Briony, which is the variation and Bryony the original.

Fresh and fragrant nature name more apt to be used for a boy.