Carrot weed (Cupaniopsis anacardioides)

Introduction:

Plants provide us with food and fiber, decorate our yards and gardens, and provide habitat for wildlife. But when plants grow where they are not wanted, we call them weeds. To home owners, weeds may be unwanted plants in lawns and gardens. To farmers, weeds are plants that interfere with raising crops or livestock. To biologists who manage natural areas, weeds are plants that interfere with the functions of natural communities.

Natural area weeds are often exotic plant species (plants whose natural range does not include Florida and were brought here after European contact, about 1500 AD) that have become naturalized (capable of reproducing outside of cultivation). Invasive exotic plants are weeds that alter the functions and value of natural areas by displacing native species (plants whose natural range included Florida at the time of European contact) and disrupting natural processes such as fire and water flow. Natural area managers must remove invasive exotic plant species to maintain the integrity of natural areas.

Carrotwood (Cupaniopsis anacardioides) is an invasive plant species in Florida that should be removed from public and private properties to help protect the state’s natural areas. Carrotwood has been listed by the Florida Exotic Pest Plant Council as one of Florida’s most invasive plant species since 1995 and was added to the Florida Noxious Weed List by the Florida Department of Agriculture and Consumer Services in 1999. Plants on the Florida Noxious Weed List may not be introduced, possessed, moved, or released without a permit.

Impacts:

Carrotwood freely seeds from plantings. Seeds are eaten by birds and dispersed away from parent plants. Consumption by fish crows is

particularly important because seeds are carried from inland feeding sites to coastal islands where they are deposited and germinate.

Fish crows eat carrotwood seeds and disperse them to coastal habitats where they germinate and are invasive.Habitats that have been invaded by carrotwood include spoil islands, beach dunes, marshes, tropical hammocks, pinelands, mangrove and cypress swamps, scrub habitats, and coastal strands. Carrotwood is especially a problem in low moist areas, is salt tolerant, and has become a pest to mangrove ecosystems. Mangrove habitats are recognized as extremely important coastal habitats and are already heavily impacted by coastal development and invasion by other exotic plants. Natural areas of 14 coastal counties in central and south Florida have been impacted by carrotwood.

Distribution:

Carrotwood is native to Australia, where it occurs on the north and east coasts on rocky beaches, sand dunes, hilly scrub, and riverine and

monsoon forests. The earliest record of carrotwood in Florida is 1955 from a cultivated plant in St. Lucie County, but it was not introduced commercially until 1968. By 1990, seedlings were found established in various habitats, disturbed and undisturbed, on both Florida coasts. It is found in private and commercial landscapes and naturalized in coastal counties from Brevard and Hillsborough south to Miami-Dade and Collier.

How to Recognize Carrotwood:

Carrotwood is an evergreen tree that is usually single-trunked and grows to 35 feet tall. The outer bark is dark grey. The tree is called carrotwood because it often has an orange colored inner bark. Carrotwood leaves are compound, alternate, and usually even-pinnate (a compound leaf whose terminal leaflets are a pair). Petioles (leaf stalks) are swollen at the base. Leaflets are 4-12, stalked, oblong, leathery, shiny yellowish-green, to 8 inches long and 3 inches wide, with untoothed margins, and tips rounded or slightly indented. Numerous white to greenish yellow flowers occur in branched clusters to 14 inches long in January and February. Fruit are the most striking identifying characteristic, being a short-stalked woody capsule to 1 inch across, with 3 distinctly ridged segments, yellow orange when ripe (April/May), drying to brown and splitting open to expose 3 shiny oval black seeds covered by a yellow-red crust.