Ruellia blechum, also known as browne's blechum, is an annual or perennial herb native to Mexico and northern South America. It grows to less than 50 cm tall with erect flower shoots and opposite, ovate, stalked leaves 2 to 7 cm long. The flowers are white or purple and arranged in dense spikes that appear squarish because of floral bracts. The fruit is an ellipsoid capsule with 2 brown circular seeds. This plant has spread to warmer places around the globe, including much of the Pacific and parts of Asia and Australia, through the ornamental plant trade. Unfortunately, it has also escaped into the wild and become something of a weedy pest. Nevertheless, Ruellia blechum is still a popular ornamental plant due to its attractive flowers and easy care requirements.