Calico flower is an evergreen, climbing vine that can grow from 10 to 15 feet in length. Leaf blades are broadly cordate, 3 to 4 inches long and 2 to 4 inches wide. Flowers are very unusual, usually greenish yellow and dark blackish purple with a tubular shape and flared at the mouth. Borne solitary in leaf axils, the flowers can be found among the foliage and reach nearly 3 inches long. Slender woody stems twine in tight coils around fence wire, other supports, or even other plants.

Aristolochia littoralis or calico flower is a cultivated ornamental vine. Native to Brazil, calico flower is grown for its colorful and unique pipe-shaped flowers. Herbal preparations have been used for various ailments and to ease the pain of childbirth, however these plants are highly toxic. Herbal supplements containing aristolochic acid or other compounds associated with members of this genus should be avoided.

 Source: http://plants.ifas.ufl.edu/node/649