Wild petunia (Ruellia humilis) belongs to the Acanthaceae (the Acanthus family). It is a perennial herb that is native to the eastern and central United States. This herb grows in dryish soils in open woods, glades, prairies and fields, and up to a height of 45-60 cm. The leaves are oblong to lanceolate, olive green and up to 10 cm long. Leaves and stems are hairy. The lavender to lilac, tubular, bell-shaped flowers bloom singly or in clusters in the upper leaf axils from May to October. It has five shallow rounded lobes.