"Transformation of parts of a flower, usually stamens or sepals, into petals or petal-like structures (as a teratological or evolutionary phenomenon)", Mid 19th cent.; earliest use found in Maxwell Tylden Masters (1833–1907), botanist and journal editor. From ancient Greek πεταλώδης leaf-like + -y, apparently after petalodic.[petalody etymology, petalody origin, 英语词源]