sentences:  The leaves are simple, and are petiolate (on short stalks), except in "O. sessilifolia", with entire or occasionally sinuate (wavy) edges.The inflorescences are loose thyrses of flowers, growing from leaf axils (axillary) or directly from the stem (cauliflory).The flowers are large, conspicuous and bisexual; the calyx is actinomorphic (rotationally symmetrical), but the corolla is zygomorphic, sometimes strongly so.