NATIVE
RANGE
Eastern Africa to India, Southeast Asia, tropical Australia,
and the Pacific Islands
DESCRIPTION
Asiatic colubrina, also
called latherleaf, because of its ability to produce a lather in water, is
a shrubby member of the buckthorn family (Rhamnaceae). It is a low
shrub with long, climbing or drooping branches that can reach 20 feet long
or more. The leaves are 1½ to 5½ inches long, egg-shaped,
and easily recognized by their shiny, green upper surfaces and toothed edges. They
are attached to stems by slender stalks and are arranged alternately along
the branches. Flowering, which usually occurs in July, produces clusters
of small, greenish-white flowers at the junctures of leaf and stem. The fruits
are small capsules, measuring less than ½ inch across, which reach
maturity as early as September. At first green and fleshy, the capsules become
dark brown with age. Each fruit contains three tiny grayish seeds.
Asiatic colubrina
should not be confused with U.S. native species of the genus (Colubrina)
that are all trees with erect branches and hairy leaves. Other
members of the buckthorn famiy include such plants as the jujube, California
lilac, and buckthorn.
ECOLOGICAL THREAT
Asiatic colubrina
produces a thick mat of tangled stems that can be several feet thick, impacting
the underlying vegetation by growing on it or shading it out. The occurrence
of Asiatic colubrina in Florida’s coastal tropical hardwood forests is of
special concern due to the uniqueness of this habitat and the rarity of some
of its constituent plant species, including a number of Florida State-listed
threatened and endangered species such as West Indian mahogany, Florida thatch
palm, wild cinnamon, manchineel, prickly-pear and dildo cacti, and a number
of bromeliads and orchids. Sites infested by colubrina experience a
great reduction in biological diversity as very few plants (including seedlings
of Asiatic colubrina itself) can persist under these conditions. Impacts
to natural areas include alterations of community composition and structure,
diminishment of natural habitats for native wildlife, disruption of species
relationships and interactions, and interference with ecological and geological
processes such as water and nutrient cycling.
DISTRIBUTION
IN THE UNITED STATES
Asiatic colubrina only occurs along the eastern
and western coastlines of central and southern Florida (more or less frost-free),
including the Florida Keys. As it is widespread throughout
the Caribbean Basin, it is also likely to occur in the U.S. possessions
of Puerto Rico and the U.S. Virgin Islands.
HABITAT IN THE UNITED STATES
Asiatic
colubrina is an upland plant that inhabits only the higher portions of coastal
areas. It can invade both disturbed and undisturbed forest sites. Coastal
forests (or hammocks) comprised of tropical hardwoods and buttonwoods are
especially vulnerable as they occur on such flood-free sites, created from
the deposition of soils left by storms and tidal influences. Natural
ridges or berms that have formed within inundated mangrove forests can also
support Asiatic colubrina. It is also frequently found along elevated
road shoulders in coastal areas, from which it can spread into adjacent natural
areas.
BACKGROUND
Asiatic colubrina is believed
to have been carried to Jamaica in the 1850s by East Asian immigrants, probably
on account of its traditional uses (food, medicine, fish poison, and soap
substitute). From there, it spread on its own to other Caribbean islands,
Mexico (Yucatan Peninsula), and Florida. The earliest known record of its
occurrence in Florida is 1937 where it was collected in the Florida Keys.
The first reports of it on the mainland are specimens collected in Everglades
National Park in the early 1950s.
BIOLOGY & SPREAD
Asiatic
colubrina reproduces sexually and vegetatively. It has been reported that
plants can flower and fruit within the first year of growth. Seeds
are believed to retain their viability in the soil for at least several (3-5)
years. Little is known about seed germination except that it requires loose
soil and does not normally occur on exposed rock.
Asiatic colubrina exhibits tremendous vegetative
regeneration, including adventitious rooting from branches coming in contact
with the soil and vigorous resprouting from cut or injured stems. Plants
require considerable light and growth rates of seedlings increase with the
removal of the shading canopy. Seedlings normally occur near larger,
reproductively mature plants, suggesting that long-distance dispersal is
uncommon. Asiatic colubrina’s buoyant and salt-tolerant seeds and fruits
are dispersed by ocean currents. Because the seeds resemble small pebbles,
it has been suggested that they may be used as crop stones by seed-eating
birds, which may disperse them long distances.
MANAGEMENT OPTIONS
Mechanical and chemical
methods are the primary means of control of Asiatic colubrina. The application
of a 10% solution of triclopyr (e.g., Garlon® 4) in a band around the base
of the trunk (basal bark method) or application of a 50% solution of the
same (e.g., Garlon® 3A) on a freshly cut trunk (cut stump method) are the
most effective ways to kill adult plants. The application of a 3% solution
of triclopyr to the foliage (foliar application method) may be used if non-target
vegetation in the immediate vicinity will not be impacted by herbicide drift.
Because of the possibility of resprouting from the rooted portions of the
plant, follow-up inspections and retreatments may be necessary for a year
(if not longer) following the initial treatment. In addition, the long viability
of seeds in the soil requires monitoring of treatment sites for several years
after the initial treatment. Seedlings and young plants, up to about 5 feet
tall, may be hand-pulled as long as their root systems are small and can
also be removed. Care should be taken not to disturb the soil any more than
necessary.
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.
CONTACTS
For more information on
the management of Asiatic Colubrina, please contact:
- David T. Jones, South Florida Natural
Resources Center, Everglades National Park, Homestead, FL; david_jones at nps.gov;
office: 305/242-7800; fax: 305/242-7836
OTHER LINKS
AUTHOR
David T. Jones, South Florida Natural Resources
Center, Everglades National Park, Homestead, FL
EDITOR
Jil M. Swearingen, National Park Service,
Washington, DC
PHOTOGRAPHS
David T. Jones, South Florida Natural Resources
Center, Everglades National Park, Homestead, FL
Mandy Tu, The Nature Conservancy, Davis, CA
REFERENCES
Jones, D.T. 1996. The Status and
Management of Colubrina asiatica (latherleaf) in Everglades National
Park. South Florida Natural Resources Center, Everglades National Park,
Homestead.
Jones, D.T. 1997. Ecological consequences
of latherleaf (Colubrina asiatica) in southern Florida. Wildland
Weeds (Winter 1997): 11-12.
Langeland, K.A. (ed.). 1998. Most
Invasive Plants of Natural Areas in Florida. Institute of Food and
Agricultural Sciences, University of Florida, Gainesville. [in press]
Langeland, K.A. and R.K. Stocker. 1997. Control
of Non-native Plants in Natural Areas of Florida – SP242. Institute of Food
and Agricultural Sciences, University of Florida, Gainesville.
The Nature Conservancy. Colubrina:
Element Stewardship Abstract. In: Wildland Weeds Management & Research
Program, Weeds on the Web.
Tomlinson, P.B. 1980. The Biology
of Trees Native to Tropical Florida. Harvard University Printing Office,
Allston.
Schultz, G.E. 1992. Stewardship
Abstract – Colubrina asiatica. The Nature Conservancy, Florida
Musuem of Natural History, Gainesville.
Plant Conservation
Alliance, Alien Plant Working Group.
|