Lead Tree Leucaena leucocephala (Lam.) Fabaceae

Biology Also known as leucaenaAlso 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, timber –Animal fodder –Windbreaks and shade Legume plant - capable of fixing nitrogenLegume plant - capable of fixing nitrogen

Background Economic Uses Introduced to Florida for animal fodder and erosion controlIntroduced to Florida for animal fodder and erosion control

Distribution Found throughout much of south and west Florida, Miami-Dade, Monroe countiesFound throughout much of south and west Florida, Miami-Dade, Monroe counties Also found in Florida KeysAlso found in Florida Keys Commonly found along roadways and disturbed areas, forest edges, coastal strandsCommonly found along roadways and disturbed areas, forest edges, coastal strands

Lead Tree Distribution in Florida

Impacts Category II invasive species (FLEPPC)Category II invasive species (FLEPPC) –Limited spread into undisturbed sites Forms dense thickets, displacing native vegetationForms dense thickets, displacing native vegetation Multiple shoots form when cut back, responds favorably to fireMultiple shoots form when cut back, responds favorably to fire

Identification

Mature Plant Shrub to small tree 15 to 20 feet in heightShrub to small tree 15 to 20 feet in height Grows in dense thicketsGrows in dense thickets –Multiple shoots –Multiple plants

Leaves Alternately arrangedAlternately arranged Bipinnate compoundBipinnate compound –6 to 20 inches long –12 to 15 leaflet pairs per branch Leaf arrangement gives mimosa fern- like or feathery appearanceLeaf arrangement gives mimosa fern- like or feathery appearance

Flowers & Seed Pods Flowers clustered on ends of branchesFlowers clustered on ends of branches Seed pods flat & green, turning brown at maturitySeed pods flat & green, turning brown at maturity 20 seed/pod, glossy brown, oval and flat20 seed/pod, glossy brown, oval and flat

Management PreventativeCulturalMechanicalBiologicalChemical

Preventative 1.Limit planting as a forage or utility crop 2.Remove existing plants, including resprouts and before seeds are produced 3.Avoid use of possibly contaminated mulch with lead tree seeds 4.Prevent seed spread and dispersal 5.Rouge out trees in abandoned areas

Cultural 1.Alternative forage and erosion control plants to replace lead tree 2.Programs to educate ranchers about the problems associated with lead tree and proper identification 3.Maintain good ground cover and mixture of plant species to reduce establishment

Biological 1.Managed grazing by cattle to prevent seed formation is effective

Mechanical 1.Hand pull young seedlings, including all roots, repeated pulling for resprouts 2.Cut tree down at ground level 3.Girdling is effective for large trees  Cut through bark approximately 6 inches above the ground, encircling tree base 4.Mowing is effective on small saplings and resprouts, but must be repeated

Chemical - Foliar 1.Over-the-top applications for seedlings, resprouts and small trees 2.Thoroughly wet leaves with herbicide Triclopyr – 2% solution Triclopyr – 2% solution Glyphosate – 2 to 3% solution Glyphosate – 2 to 3% solution Clopyralid to 0.4% solution Clopyralid to 0.4% solution Use surfactant at 0.25% Use surfactant at 0.25% 3.Best results applied July to October

Chemical - Basal 1.Individual trees, near desirable species 2.Use 25% triclopyr solution with basal oil 3.Apply 12 to 15 inches above ground on tree trunk 4.Wet thoroughly for good control, spray until run-off is noticeable at ground line

Chemical – Cut Stump 1.Individual trees, near desirable species 2.Cut trunks/stems horizonally at or near ground level 3.Apply 25% solution of glyphosate or triclopyr 4.Cover the outer 20% of the stump 5.Marker (blue) dye is helpful

Useful Links Floridata Homepage: University of Florida Center for Aquatic and Invasive Plants: University of Florida’s Cooperative Extension Electronic Data Information Source:

Useful Links The Plant Conservation Alliance's Alien Plant Working Group. Weeds Gone Wild: Alien Plant Invaders of Natural Areas: Pacific Island Ecosystems at Risk (PIER). Plant Threats to Pacific Ecosystems: USDA Natural Resources Conservation Service. Plants Database:

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