Ruellia is a genus of flowering plants commonly known as ruellias or wild petunias. They are not closely related to petunias (Petunia) although both genera belong to the same euasterid clade. The genus was named in honor of Jean Ruelle, herbalist and physician to Francis I of France and translator of several works of Dioscorides. Apart from the numerous formerly independent genera nowadays considered synonymous with Ruellia, the segregate genera Blechum, Eusiphon, Polylychnis and Ulleria are often included in Ruellia. Acanthopale, however, is considered a distinct genus.