Trailing lantana [Lantana montevidensis (Spreng.) Briq.] is a low-growing, woody shrub or sprawling groundcover native to tropical areas of South America. The leaves are simple, opposite, rugose, ovate in shape, with dentate margins and a pungent odor when crushed. The attractive umbel inflorescences are typically lavender in color with varying degrees of white and/or yellow in the center of corolla tubes. Flowers are followed by an infructescence of ellipsoid drupes turning from green to purple when ripe (Dehgan, 1998).
As early as 1825, the species was described by the German botanist Curt Polycarp Joachim Sprengel (Johnson, 2007, 2009). It has since escaped cultivation and is considered invasive in many subtropical ecosystems from Hawaii, Australia, and the Southeast United States. The invasiveness of trailing lantana is attributed to several factors, including 1) its ability to produce large amounts of fruit that are dispersed by birds, 2) the presence of an underground storage organ (xylopodium) facilitating its resilience to fire, drought, and herbicide, 3) its potential to produce two embryos per seed (apomixis) that germinate under a range of conditions, and 4) its ability to spread vegetatively (O’Donnell, 2002). Due to its rapid expansion and colonization of native lands and improved pastures in Australia, trailing lantana is a restricted invasive prohibited for use by the Queensland Biosecurity Act of 2014 (Johnson, 2007, 2009; Munir, 1996; O’Donnell, 2002). In the United States, it has escaped cultivation in seven states, including Alabama, California, Florida, Georgia, Hawaii, Louisiana, and Texas [U.S. Department of Agriculture, National Resources Conservation Service (USDA, NRCS), 2020]. In Florida, herbarium vouchers have documented its escape in 18 counties (Wunderlin et al., 2020).
To date, trailing lantana has not been listed as a Category I or II invasive plant by Florida’s Exotic Pest Plant Council (FLEPPC, 2019). However, based on a predictive test, the University of Florida/Institute of Food and Agricultural Sciences’ (UF/IFAS) Assessment of Non-Native Plants in Florida’s Natural Areas does not recommend its use in northern, central, or south Florida, because it has a high invasion risk (UF/IFAS Assessment, 2020a). The predictive tool used to make this conclusion is a weed risk assessment protocol consisting of 49 questions that address the history of the species, along with its biogeography, life history traits, and ecology (Lieurance et al., 2016). Each question receives a numerical score between −3 and 5 points, and conclusions are made based on the cumulative score. Any score greater than 6 means a high risk of invasion. Trailing lantana received a score of 29 and is therefore not recommended for use in Florida (UF/IFAS Assessment, 2020b). Specifically, the species scored a value greater than 0 for 25 of the 49 questions, with heavier weighted scoring designated due to it being a weed of agriculture (4 points), a weed of environmental harm (4 points), a garden weed (2 points), a congeneric weed sharing the genus of the highly invasive Lantana camara L. (2 points), and the documented naturalization beyond its native range (2 points). In Florida, all cultivars fall under this classification unless proven otherwise through an internally approved UF/IFAS Infraspecific Taxon Protocol (ITP) evaluation. This protocol consists of 12 questions to determine 1) if the taxon displays invasive traits that cause greater ecological impact than the wild type or resident species and if it can be readily distinguished; and 2) the fecundity of the taxon and its chances of regression or hybridization to characteristics of the resident/wild type species (Lieurance et al., 2016).
Interestingly, in Australia two forms of trailing lantana have been reported that differ in their ability to produce fruit (Johnson, 2007, 2009). Steppe et al. (2019) obtained a permit to import germplasm from the fruiting Australian form into the United States. They also collected different U.S. forms sold from various nurseries in Florida and a naturalized form from Texas. A total of eight different varieties of trailing lantana were evaluated for morphological and cytological distinctions. It was discovered that Australian trailing lantana differed morphologically and cytologically from the U.S. varieties (Steppe et al., 2019). Most noticeably, leaves of Australian trailing lantana were smaller with fewer leaf serrations, distinct serrate-crenate margins, and less appressed hairs. Also, well-developed, stainable pollen grains were observed in the anther sacs of the Australian trailing lantana but absent in U.S. varieties. Finally, the Australian trailing lantana was determined to be a tetraploid, but all U.S. varieties evaluated were triploids. The current study was conducted to explore the landscape performance, flowering, and female fertility of these eight trailing lantana varieties planted in replicated field trials at two locations in Florida.
Czarnecki, D.M. & Deng, Z. 2020 Assessment of the female fertility of 26 commercial Lantana camara cultivars and six experimental lines HortScience 55 709 715
Czarnecki, D.M., Wilson, S.B., Knox, G.W., Freyre, R. & Deng, Z. 2012 UF-T3 and UF-T4: Two sterile Lantana camara cultivars HortScience 47 132 137
Czarnecki, D.M., Hershberger, A.J., Robacker, C.D., Clark, D.G. & Deng, Z. 2014 Ploidy levels and pollen stainability of Lantana camara cultivars and breeding lines HortScience 49 1271 1276
Day, M., Wiley, C.J., Playford, J. & Zalucki, M.P. 2003 Lantana: Current management status and future prospects. Austral. Ctr. Intl. Agr. Res., Canberra, Australia
Deng, Z., Wilson, S.B., Ying, X. & Czarnecki D.M. II 2017 Infertile Lantana camara cultivars UF-1011-2 and UF-1013A-2A HortScience 52 652 657
Florida Exotic Pest Plant Council (FLEPPC) 2019 Florida Exotic Pest Plant Council’s 2019 list of invasive species. 20 May 2019. <https://www.fleppc.org/list/list.htm>
Gallagher, R.V., Randall, R.P. & Leishman, M.R. 2014 Trait differences between naturalized and invasive plant species independent of residence time and phylogeny Conserv. Biol. 29 360 369
Johnson, S.B. 2007 Review of the declaration of lantana species in New South Wales. Dept. Primary Ind., Orange NSW, Australia
Johnson, S.B. 2009 Lantana montevidensis (Spreng.) Briq., p. 128–142. In: F.D. Panetta (ed.). The biology of Australian weeds, vol. 3. R.G. and F.J. Richardson, Melbourne, Australia
Lieurance, D., Flory, S.L. & Gordon, D.R. 2016 The UF/IFAS assessment of nonnative plants in Florida’s natural areas: History, purpose, and use. 15 Dec. 2019. <https://edis.ifas.ufl.edu/pdffiles/AG/AG37600.pdf>
Munir, A.A. 1996 A taxonomic review of Lantana camara L. and L. montevidensis (Spreng.) Briq. (Verbenaceae) in Australia J. Adel. Bot. Gard. 17 1 27
Negi, G.C.S., Sharma, S., Vishvaharma, S.C.R., Samant, S.S., Maikhuri, R.K., Prasad, R.C. & Palni, L.M.S. 2019 Ecology and use of Lantana camara in India Bot. Review 85 109 130
O’Donnell, C. 2002 The creeping lantana handbook. A guide to ecology, control and management. Queensland Dept. Primary Ind., Natl. Resources and Mines, Brisbane, Australia
Rihan, H.Z., Al-Issawi, M., Al-Swedi, F. & Fuller, M.P. 2012 The effect of using PPM (plant preservative mixture) on the development of cauliflower microshoots and the quality of artificial seed produced Scientia Hort. 141 47 52
Steppe, C., Wilson, S.B., Deng, Z., Druffel, K. & Knox, G.W. 2019 Morphological and cytological comparisons of eight varieties of trailing lantana (Lantana montevidensis) grown in Florida HortScience 54 2134 2138
University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) 2020a Assessment of nonnative plants in Florida’s natural areas. Lantana montevidensis. 2 Jan. 2020. <https://assessment.ifas.ufl.edu/assessments/lantana-montevidensis/>
University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) 2020b Assessment of nonnative plants in Florida’s natural areas. Lantana montevidensis weed risk assessment. 7 July 2020. <https://assessment.ifas.ufl.edu/site/assets/files/3652/lantana_montevidensis_wra.pdf>
U.S. Department of Agriculture (USDA), Agricultural Research Service 2012 Plant hardiness zone map. 15 Jan. 2020. <https://planthardiness.ars.usda.gov>
U.S. Department of Agriculture, National Resources Conservation Service 2020 The PLANTS database. Natl. Plant Data Team, Greensboro, NC. 20 May 2019. <htpp://plants.usda.gov>
van Kleunen, M., Weber, E. & Fischer, M. 2010 A meta-analysis of trait differences between invasive and non-invasive plant species Ecol. Lett. 13 235 245
Wijayabandara, S.M.K.H., Jayasuriya, K.M.G.G. & Jayasinghe, J.L.D.H.C. 2013 Seed dormancy, storage behavior and germination of an exotic invasive species, Lantana camara L. (Verbenaceae) Intl. Res. J. Biol. Sci. 2 7 14
Wunderlin, R.P., Hansen, B.F., Franck, A.R. & Essig, F.B. 2020 Atlas of Florida plants. Inst. Systemic Bot., Univ. South Florida, 2 Jan. 2020. <http://florida.plantatlas.usf.edu>