Australia, Irian Jaya (Indonesia) and Papua New Guinea
is a fast-growing evergreen tree that grows to a height of about 35 feet.
The leaves are large and compound, made up of four to ten oblong leaflets,
each 4 to 8 inches long, and attached by a swollen stalk. Leaflet edges tend
to be wavy with rounded tips that are often indented. Leaves alternate along
the stems. In Florida, flowering occurs in the winter, from January to March.
Clusters of small, greenish-white flowers are borne on stalks that emerge
from leaf axils. Flowers are unisexual, with each flower cluster containing
both male and female flowers. The brightly colored fruit is a yellow, three-lobed
capsule which, when ripe (May to June) splits open to expose three shiny
black seeds encased in red or orange fleshy tissue.
As of July 1999, carrotwood has been added to the State of Florida List
of Noxious Weeds.
While carrotwood invades
a variety of natural communities, including dunes, coastal strand, sand pine
scrub, slash pine flatwoods, cypress swamps, freshwater marshes and river
banks, it poses a special threat to coastal ecosystems like mangrove swamps
and tropical hammocks. Coastal plant communities provide crucial erosion
control, water quality benefits, and food and shelter for wildlife. Once
introduced, carrotwood forms dense monocultures, crowding out and out-competing
native plants for available light and nutrients.
Because mangroves provide critical habitat for
wading and diving birds, some of which are designated Species of Special
Concern, and serve as nursery grounds for crabs, other crustaceans, invertebrates
and commercial and recreational fish, the impacts of carrotwood establishment
are serious and far-reaching. Coastal hammocks and mangroves are continually
losing ground to development and are also impacted by natural forces such
as tropical storms and hurricanes. Alteration of species composition and
competition by invasive exotic species increases stress to the remaining
hammocks. Because carrotwood is a popular, fast-growing landscape tree that
is widely planted and very adaptable, the impacts to mangroves and other
habitats are expected to increase. Carrotwood has also been found growing
among other aggresive, invasive exotic trees.
IN THE UNITED STATES
As of 1996, carrotwood has been documented to
occur in natural areas in fourteen Florida counties, from Brevard and Hillsborough
counties, southward. The current distribution of carrotwood parallels that
of mangrove tree species. While naturalized carrotwood infestations are
limited primarily to coastal areas, inland populations are beginning to
surface. Carrotwood has also been used ornamentally in California, but
there are no reports of naturalized populations there, perhaps due to their
drier climate. Cold tolerance may limit its potential distribution. According
to one reference, carrotwood is able to withstand temperatures to about
22 F (-6 C). Test specimens in northern Florida, however, have withstood
winters at least that cold.
HABITAT IN THE UNITED STATES
of salt, poor soils, poor drainage, sunlight and shade, carrotwood can adapt
to dry areas, and appears in disturbed and undisturbed sites. As a result,
carrotwood inhabits a variety of habitats including coastal hammocks, dunes,
coastal strand, sand pine scrub, slash pine flatwoods, mangrove swamps, cypress
swamps, freshwater marshes and river banks.
University of Florida Herbarium
specimens document carrotwood cultivation as early as 1955 in eastern Florida.
A separate introduction in Sarasota, Florida in 1968 resulted in large scale
propagation and use as an ornamental tree. Carrotwood became a popular landscape
tree throughout southern Florida in the late 1970s and early 1980s. By 1990,
wild carrotwood seedlings began to be seen in the wild in various habitats.
BIOLOGY & SPREAD
Carrotwood is a
prolific seed producer, and the brightly colored fruits are very attractive
to birds which disperse it widely. Bird dispersal explains isolated island
populations and seedlings under trees and telephone poles. Seedlings have
also been found along estuary rack lines. Clumps of seedlings suggest dispersal
by small mammals. In its native range, carrotwood is pollinated by bees,
which are the likely pollinators in Florida.
No biological control
is available at this time. Chemical control is the most common and effective
method of control. Triclopyr (e.g., Garlon) has proved effective as a basal
bark treatment and cut stump treatment. Glyphosate (e.g., Rodeo®) is marginally
successful, and usually requires retreatment. Care must be taken in mangrove
and wetland areas to avoid impacts to sensitive flora and fauna by use of
chemicals or heavy equipment. As a preventive measure, a few counties and
municipalities have ordinances restricting use of carrotwood.
USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS.
NOTICE: MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.
For more information on
the management of carrotwood, please contact:
- Ed Freeman, Natural Resources Department,
Resource Management Division 1301, Cattlemen Road Sarasota, FL 34232, (941)
378-6142, efreeman at co.sarasota.fl.us
- Chris Lockhart, Habitat Specialists Inc. http://www.lockharts.org/Habitat_Specialists, chris at lockharts.org
- Roger Clark, Lee County Parks and Recreation,
rogersclark at juno.com
SUGGESTED ALTERNATIVE PLANTS
trees make good landscape substitutes for carrotwood. In southern Florida, alternatives
include paradise tree (Simarouba glauca), pigeon plum (Coccoloba diversifolia),
Jamaican dogwood (Piscidia piscipula), and inkwood (Exothea paniculata).
In northern and central Florida, there's loblolly bay (Gordonia lasianthus),
laurel cherry (Prunus carolinana) and magnolias (Magnolia virginiana or M.
grandiflora). Dahoon holly (Ilex casseine) has a broad range and colorful
Chris Lockhart, Habitat Specialists, Inc., Boynton
Jil M. Swearingen, National Park Service,
Chris Lockhart, Habitat Specialists, Inc., Boynton
Forest & Kim Starr, US Geological Survey, HI
Hawkeswood, T.J. 1983. Pollination
and fruit production of Cupaniopsis anacardioides (A. Rich.)
Radlkf. (Sapindaceae) in Townsville, North Queensland. 1. Pollination and
floral biology. Victorian Naturalist. 100: 12-20.
Lockhart, C.S., D. Austin, L. Downey,
and B. Jones. 1999. The Invasion of Carrotwood (Cupaniopsis anacardioides)
in Florida Natural Areas (USA). Natural Areas Journal 19(3): 254-262.
Oliver, J.D. 1992. Carrotwood: A
Review of the Literature. Florida Department of Environmental Protection,
Bureau of Aquatic Plant Management.
Reynolds, S.T. 1985. Sapindaceae.
Flora of Australia 25, pp. 4-163.
Stresau, F.B. 1986. Florida, My
Eden. Florida Classics Library. Port Salerno, FL.
Swearingen, J. 2009. WeedUS Database of Plants Invading Natural Areas in the United States: Carrotwood (Cupaniopsis anacardioides). http://www.invasive.org/weedus/subject.html?sub=5401.
USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Plant Conservation Alliance, Alien Plant Working Group.