Lead TreeLead Tree Leucaena leucocephala Leucaena leucocephala

(Lam.) Fabaceae(Lam.) Fabaceae

BiologyBiology• Also known as leucaena Also known as leucaena

• Shrub or small tree < 20 feet tallShrub or small tree < 20 feet tall

• Native to Mexico and Central AmericaNative to Mexico and Central America– Used for fuel wood, timberUsed for fuel wood, timber

– Animal fodderAnimal fodder

– Windbreaks and shadeWindbreaks and shade

• Legume plant - capable of fixing nitrogenLegume plant - capable of fixing nitrogen

BackgroundBackgroundEconomic UsesEconomic Uses

• Introduced to Introduced to Florida for animal Florida for animal fodder and fodder and erosion controlerosion control

DistributionDistribution• Found throughout much of south Found throughout much of south

and west Florida, Miami-Dade, and west Florida, Miami-Dade, Monroe countiesMonroe counties

• Also found in Florida KeysAlso found in Florida Keys

• Commonly found along roadways Commonly found along roadways and disturbed areas, forest edges, and disturbed areas, forest edges, coastal strandscoastal strands

Lead Tree Distribution in FloridaLead Tree Distribution in Florida

ImpactsImpacts• Category II invasive species (FLEPPC)Category II invasive species (FLEPPC)

– Limited spread into undisturbed sitesLimited spread into undisturbed sites

• Forms dense thickets, displacing native Forms dense thickets, displacing native vegetationvegetation

• Multiple shoots form when cut back, Multiple shoots form when cut back, responds favorably to fireresponds favorably to fire

IdentificationIdentification

Mature PlantMature Plant• Shrub to small Shrub to small

tree 15 to 20 feet tree 15 to 20 feet in heightin height

• Grows in dense Grows in dense thicketsthickets– Multiple shootsMultiple shoots– Multiple plantsMultiple plants

LeavesLeaves• Alternately arrangedAlternately arranged• Bipinnate compound Bipinnate compound

–6 to 20 inches long6 to 20 inches long–12 to 15 leaflet pairs 12 to 15 leaflet pairs

per branchper branch• Leaf arrangement Leaf arrangement

gives mimosa fern-like gives mimosa fern-like or feathery appearanceor feathery appearance

Flowers & Seed PodsFlowers & Seed Pods• Flowers clustered Flowers clustered

on ends of on ends of branchesbranches

• Seed pods flat & Seed pods flat & green, turning green, turning brown at maturitybrown at maturity

• 20 seed/pod, 20 seed/pod, glossy brown, oval glossy brown, oval and flatand flat

ManagementManagementPreventativePreventative

CulturalCultural

MechanicalMechanical

BiologicalBiological

ChemicalChemical

PreventativePreventative1.1. Limit planting as a forage or utility cropLimit planting as a forage or utility crop

2.2. Remove existing plants, including Remove existing plants, including resprouts and before seeds are resprouts and before seeds are producedproduced

3.3. Avoid use of possibly contaminated Avoid use of possibly contaminated mulch with lead tree seedsmulch with lead tree seeds

4.4. Prevent seed spread and dispersalPrevent seed spread and dispersal

5.5. Rouge out trees in abandoned areasRouge out trees in abandoned areas

CulturalCultural1.1. Alternative forage and erosion control Alternative forage and erosion control

plants to replace lead treeplants to replace lead tree

2.2. Programs to educate ranchers about Programs to educate ranchers about the problems associated with lead the problems associated with lead tree and proper identificationtree and proper identification

3.3. Maintain good ground cover and Maintain good ground cover and mixture of plant species to reduce mixture of plant species to reduce establishmentestablishment

BiologicalBiological1.1. Managed grazing by cattle to prevent Managed grazing by cattle to prevent

seed formation is effectiveseed formation is effective

MechanicalMechanical1.1. Hand pull young seedlings, including Hand pull young seedlings, including

all roots, repeated pulling for resproutsall roots, repeated pulling for resprouts

2.2. Cut tree down at ground levelCut tree down at ground level

3.3. Girdling is effective for large treesGirdling is effective for large trees Cut through bark approximately 6 inches Cut through bark approximately 6 inches

above the ground, encircling tree baseabove the ground, encircling tree base

4.4. Mowing is effective on small saplings Mowing is effective on small saplings and resprouts, but must be repeatedand resprouts, but must be repeated

Chemical - FoliarChemical - Foliar1.1. Over-the-top applications for seedlings, Over-the-top applications for seedlings,

resprouts and small treesresprouts and small trees

2.2. Thoroughly wet leaves with herbicideThoroughly wet leaves with herbicide Triclopyr – 2% solutionTriclopyr – 2% solution Glyphosate – 2 to 3% solutionGlyphosate – 2 to 3% solution Clopyralid - 0.2 to 0.4% solutionClopyralid - 0.2 to 0.4% solution Use surfactant at 0.25% Use surfactant at 0.25%

3.3. Best results applied July to OctoberBest results applied July to October

Chemical - BasalChemical - Basal1.1. Individual trees, near desirable speciesIndividual trees, near desirable species

2.2. Use 25% triclopyr solution with basal Use 25% triclopyr solution with basal oiloil

3.3. Apply 12 to 15 inches above ground on Apply 12 to 15 inches above ground on tree trunktree trunk

4.4. Wet thoroughly for good control, spray Wet thoroughly for good control, spray until run-off is noticeable at ground lineuntil run-off is noticeable at ground line

Chemical – Cut StumpChemical – Cut Stump

1.1. Individual trees, near desirable speciesIndividual trees, near desirable species

2.2. Cut trunks/stems horizonally at or near Cut trunks/stems horizonally at or near ground levelground level

3.3. Apply 25% solution of glyphosate or Apply 25% solution of glyphosate or triclopyrtriclopyr

4.4. Cover the outer 20% of the stumpCover the outer 20% of the stump

5.5. Marker (blue) dye is helpful Marker (blue) dye is helpful

Useful LinksUseful Links• Floridata Homepage:

http://www.floridata.com • University of Florida Center for Aquatic

and Invasive Plants: http://aquat1.ifas.ufl.edu/welcome.html

• University of Florida’s Cooperative Extension Electronic Data Information Source: http://edis.ifas.ufl.edu/index.html

Useful LinksUseful Links• The Plant Conservation Alliance's Alien

Plant Working Group. Weeds Gone Wild: Alien Plant Invaders of Natural Areas: http://www.nps.gov/plants/alien/index.htm

• Pacific Island Ecosystems at Risk (PIER). Plant Threats to Pacific Ecosystems: http://www.hear.org/pier/threats.htm

• USDA Natural Resources Conservation Service. Plants Database: http://plants.usda.gov.

Literature CitedLiterature CitedLangeland, K.A. and K. Craddock Burks. Langeland, K.A. and K. Craddock Burks. 1998. Identification and Biology of Non-1998. Identification and Biology of Non-Native Plants in Florida's Natural Areas. Native Plants in Florida's Natural Areas. IFAS Publication SP 257. University of IFAS Publication SP 257. University of Florida, Gainesville. 165 ppFlorida, Gainesville. 165 pp