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.
If you are ever close enough to smell the flowers of this plant, resist the temptation. Flowers of this plant produce an odor similar to that of rotting meat. The odor attracts flies to the flower where they pollinate the flower and lay their eggs. Calico flower has been reported as naturalized in parts of northern and central Florida.
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.
Spread of the plant is accomplished via seed and humans. The seed pod of A. littoralis is a dehiscent capsule with numerous winged seeds. Because the seeds are winged, they are readily dispersed by wind. Humans also spread the plant either in seed form or cuttings for ornamental purposes. Plants can be established from cuttings, but it is uncertain if these are a concern to natural areas.
Calico flower has been shown to escape cultivation in many areas of the world, including Florida. It has the ability to weigh down native plants and cause collapse under of the mass of vegetation produced. This creates an opening for opportunistic weeds to invade and take over an area. When the winged seeds of calico flower are dispersed, they will germinate wherever they land. This species is difficult to control once established because of above and below ground stems and roots that require numerous herbicide applications.
The first step in preventative control of calico vine is to limit planting and removal of existing plants within the landscape. If possible, removal should occur before seeds are produced. Care must be exercised to prevent seed spread and dispersal during the removal process.
Inform the public to refrain from purchasing, propagating, or planting A. littoralis due to the ability to escape into natural areas.
Cutting is possible, although application of an herbicide may be required to control resprouting. Small seedlings can be hand pulled.
There are no known biological control programs for A. littoralis.
Use a basal bark application of triclopyr at 100% to the base of the vine, as close to the root as possible. Do not cut vines. Repeat herbicide applications may be necessary to control regrowth or plants missed in the initial application.
Langeland, K.A. and K. Craddock Burks. 1998. Identification and Biology of Non-Native Plants in Florida's Natural Areas. IFAS Publication SP 257. University of Florida, Gainesville. 165 pp.
The Plant Conservation Alliance's Alien Plant Working Group. Weeds Gone Wild: Alien Plant Invaders of Natural Areas
Excerpted from the University of Florida, IFAS Extension, Circular 1529, Invasive Species Management Plans for Florida, 2008 by:
Greg MacDonald, Associate Professor Jay Ferrell, Assistant Professor and Extension Weed Specialist
Brent Sellers, Assistant Professor and Extension Weed Specialist
Ken Langeland, Professor and Extension Weed Specialist Agronomy Department, Gainesville and Range Cattle REC, Ona
Tina Duperron-Bond, DPM – Osceola County
Eileen Ketterer-Guest, former Graduate Research Assistant
1. Identification and Biology of Nonnative Plants in Florida’s Natural Areas – Second Edition, by K.A. Langeland, H.M. Cherry, et al. University of Florida-IFAS Publication # SP 257. 2008.