Ruellia Simplex, also known as the Mexican Petunia, is a fast-growing, shrubby perennial plant native to Central and South America and the Caribbean. It's known for its purple, funnel-shaped flowers with five petals. It can grow 3–4 ft tall in the wild, but usually 2–3 ft in gardens. It has dark green, linear leaves that can be 6–12 in long and 0.75 in wide.