Evergreen perennial, up to 1 m tall, forming colonies of stalks with lance-shaped leaves (15-30 cm long, 2 cm wide), opposite. Flowers trumpet-shaped, metallic blue to purple, with five petals.

Native to Mexico, the Caribbean and South America. Grown around the world as an ornamental. It has become a widespread invasive plant in Florida, where it was introduced as an ornamental.

No known.

The risk of introduction of Mexican Ruellia is very high. Even though this species has been listed as invasive in many areas of the world, it is still widely commercialized as an ornamental.