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 (1474–1537), 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. Ruellias are popular ornamental plants. Some are used as medicinal plants, but many are known or suspected to be poisonous. Their leaves are food for the caterpillars of several Lepidoptera (butterflies and moths), typically Nymphalinae and in particular members of their tribe Junoniini, such as the larvae of the banded peacock (Anartia fatima). Nymphalinae using Ruellia as host plants include the common buckeye (Junonia coenia), recorded on R. nodiflora, the lemon pansy (Junonia lemonias), recorded on R. tuberosa, and the malachite butterfly (Siproeta stelenes) and Australian lurcher (Yoma sabina), which are recorded on several species. Selected species Ruellia acutangula Ruellia affinis (Schrad.) Lindau Ruellia angustior Ruellia asperula Ruellia blumei Steud. Ruellia bourgaei Hemsl. Ruellia brevicaulis Ruellia brevifolia (Pohl) C.Ezcurra – tropical wild petunia, red Christmas pride Ruellia capitata Ruellia caroliniensis (J.F.Gmel.) Steud. Ruellia cernua Roxb. Ruellia chartacea (T.Anderson) Wassh. Ruellia ciliatiflora Hook. Ruellia ciliosa Pursh Ruellia colorata (might belong in R. trivialis) Ruellia currorii Ruellia densa Ruellia devosiana Jacob-Makoy ex E.Morren Ruellia dielsii Ruellia diffusa Ruellia dioscoridis Ruellia dissitifolia Ruellia drymophila Hand.-Mazz. Ruellia elegans Poir. Ruellia eriocalyx Ruellia eurycodon Ruellia flava Ruellia formosa Ruellia fulgida Andrews Ruellia geminiflora – ipecacuanha-da-flor-roxa (Portuguese) Ruellia glanduloso-punctata Ruellia hapalotricha Ruellia helianthemum Ruellia humilis Nutt. – fringeleaf wild petunia, plains petunia, fringeleaf ruellia, hairy ruellia, low ruellia, zigzag ruel Ruellia hypericoides Ruellia incomta Ruellia insignis Ruellia jaliscana Standl. Ruellia kuriensis Ruellia macrantha (Nees) Gower – Christmas pride Ruellia macrophylla Vahl Ruellia makoyana Hort.Makoy ex Closon Ruellia mcvaughii T.F. Daniel Ruellia menthoides Ruellia neesiana Ruellia nitens Ruellia noctiflora Ruellia novogaliciana T.F. Daniel Ruellia nudiflora (Engelm. & A.Gray) Urb. Ruellia patula Ruellia paulayana Ruellia pedunculata Ruellia pohlii Ruellia portellae (might belong in R. trivialis) Ruellia prostrata Poir. Ruellia puri Ruellia rasa Ruellia rosea (Nees) Hemsl. Ruellia rufipila Ruellia salicifolia Ruellia simplex C.Wright Ruellia sindica Ruellia spissa Leonard Ruellia squarrosa (Fenzl) Cufod. Ruellia stemonacanthoides (Oerst.) Hemsl. Ruellia stenandrium Ruellia strepens