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Publication #SS-AGR-165

Natural Area Weeds: Carrotwood (Cupaniopsis anacardioides)1

K.A. Langeland2

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.

Some invasive exotic plants were brought here for landscape uses and escaped into natural areas by natural dispersal of seeds or when yard waste was dumped in natural areas. Property owners can help protect natural areas by removing invasive exotic species from their land, thus preventing the spread.

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 (5b-57.007 FAC) 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 (Menninger 1964). Seeds are eaten by birds and dispersed away from parent plants (Lockhart et al. 1999, Coile 1997). 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 (Lockhart et al. 1999). Consumption by fish crows (Figure 1) is particularly important because seeds are carried from inland feeding sites to coastal islands where they are deposited and germinate (Lockhart et al. 1999). Carrotwood is somewhat salt tolerant but not to the extent of mangroves species (Langeland unpublished data). Regardless, the threat of carrotwood to coastal plant communities is a concern. Coastal habitats are extremely important to Florida and are already heavily impacted by development and invasion by other exotic plants. Natural areas of 14 coastal counties in central and south Florida have been impacted by carrotwood (Langeland et. al. 2008).

Figure 1. 

Fish crows eat carrotwood seeds and disperse them to coastal habitats where they germinate and are invasive.


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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 (Reynolds 1985). 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 (Coile 1997). By 1990, seedlings were found established in various habitats, disturbed and undisturbed, on both Florida coasts (Oliver 1990). It is found in private and commercial landscapes and naturalized in coastal counties from Brevard and Hillsborough south to Miami-Dade and Collier (Langeland and Burks 1998).

How to Recognize Carrotwood

Carrotwood is an evergreen tree (Figure 2) 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) (Figure 3). 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 (Figure 3) 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 (Figure 4).

Figure 2. 

Carrotwood planted as shade tree at Lake Wyman Park, Boca Raton, Florida.


Credit: Chris Lockhart
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Figure 3. 

Carrotwood flowers and leaves.


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Figure 4. 

Carrotwood fruits.


Credit: Chris Lockhart
[Click thumbnail to enlarge.]

Remove Carrotwood from Your Property to Protect Florida's Natural Areas

Homeowners can help mitigate the problem of carrotwood trees in Florida's natural areas by removing them from their property. Mature trees should be felled with a chain saw by the property owner or a professional tree service. The final cut should be made as close to the ground as possible and as level as possible to facilitate application of a herbicide to prevent sprouting. Stumps that are not treated with a herbicide will sprout to form multiple-trunked trees. If it is not objectionable for dead trees to be left standing, certain herbicides can be applied directly to the bark at the base of the tree (basal bark application).

Herbicides that contain the active ingredient triclopyr amine (e.g., Brush-B-Gon, Garlon 3A Ultra) or glyphosate (e.g., Roundup) can be applied to cut stumps to prevent resprouting. The herbicide should be applied as soon as possible after felling the tree and concentrated on the thin layer of living tissue (cambium) that is just inside the bark. Herbicides with the active ingredient triclopyr ester can be used for basal bark applications. Concentrated products (e.g., Garlon 4) must be diluted according to instructions on the herbicide label with a penetrating oil manufactured for this purpose, Herbicide products are available for basal bark application that are pre-diluted with penetrating oil (e.g., Pathfinder II). It is illegal to use a herbicide in a manner inconsistent with the label's instructions; therefore, read the label carefully and follow the instructions.

If trees are cut at a time when seeds are attached, make sure that the material is disposed of in such a way the seeds will not be dispersed to new areas where they can germinate and produce new trees. Seedlings should be continually pulled by hand before they reach seed-bearing maturity. The Cooperative Extension Service Office in your county can provide information on herbicide availability and application training.

Dispose of any debris that contains carrotwood seed in such a way that seeds will not be introduced to new areas. For example, dispose of on-site where seeds can be monitored for germination and seedlings pulled and destroyed or in a landfill where they will be incinerated.

Replace with Non-invasive Species

Carrotwood trees can be replaced with noninvasive species that will provide the same functions, such as shade and wildlife attraction. Table 1 lists some landscape plants that are appropriate for replacing carrotwood trees. Fact sheets that provide additional information on landscape plants can be viewed at http://hort.ifas.ufl.edu/database/trees/trees_scientific.shtml. For information on the availability of native landscape plant species, contact the Association of Florida Native Nurseries (877/353-2366 or http://www.afnn.org). The Cooperative Extension Service Office in your county can help you identify plants appropriate to your property conditions, the ecosystems on and near your site, and your aesthetic desires.

Additional Information About Invasive Plant Species

Center for Aquatic and Invasive Plants website http://plants.ifas.ufl.edu.

Florida Exotic Pest Plant Council website http://fleppc.org.

Help Protect Floridas Natural Areas from Non-Native Invasive Plants. K.A. Langeland. 1999. IFAS Circular 1204.

Identification and Biology of Non-Native Plants in Floridas Natural Areas. Second edition 2008. K.A. Langeland, H.M. Cherry, C.M. McCormick, and K. Craddock Burks. 193 pp. 1998. IFAS Publication SP 257.

Integrated Management of Nonnative Plants in Natural Areas of Florida, K. A. Langeland, J. A. Ferrell, B. Sellers, G. E. MacDonald, and R. K. Stocker. 2011. http://edis.ifas.ufl.edu/wg209.

Literature Cited

Coile, N. C. 1997. Risk Assessment for Carrotwood. Memorandum to Connie Riherd, Assistant Director, Division of Plant Industry.

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. 193 pp.

Lockhart, C. S., D. F. Austin, W. E. Jones, and L. A. Downey. 1999. Invasion of Carrotwood (Cupaniopsis anacardioides) in Florida Natural Areas (USA). Natural Areas Journal 19:254-262.

Menninger, E. A. 1964. Seaside Plants of the World. New York: Hearthside Press Inc. 303 pp.

Oliver, J. D. 1992. Carrotwood: a review of the literature. Tech. Report. Tallahassee: Florida Department of Environmental Protection, Bureau of Aquatic Plant Management. 10 pp.

Reynolds, S. T. 1985. Sapindaceae, p. 4-163. In: George, A. S., ed. Flora of Australia, Volume 25, Melianthaceae to Simaroubaceae. Australian Government Publishing Service, Canberra.

Tables

Table 1. 

Some landscape plants for replacing carrotwood trees after removal.

Botanical name

Common name

USDA Cold Hardiness Zones

Bursera simaruba

Gumbo limbo

10B-11

Chrysophyllum oliviforme

Satin leaf

10B-11

Coccoloba diversifolia

Pigeon plum

10B-11

Conocarpus erectus

Buttonwood

10B-11

Cordia sabestena

Geiger tree

10B-11

Eugenia confusa

Red stopper

10B-11

Ilex cassine

Dahoon holly

7-11

Ilex vomitoria

Yaupon holly

7-9

Myrcianthes fragrans

Simpson's Stopper

10-11

Persea borbonia

Sweetbay

7B-11

Sapindus saponaria

Florida soapberry

10-11

Simarouba glauca

Paradise tree

10B-11

Sweitenia mahagoni

Mahogany

10B-11

Tabebuia spp. (exotic)

Tabebuia

10-11

Footnotes

1.

This document is SS-AGR-165, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date May 2001. Revised May 2012. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

K.A. Langeland, professor, Agronomy Department, Center for Aquatic and Invasive Plants, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.