Lantana camara_Neal Kramer
Photo by Neal Kramer

Lantana camara Risk Assessment

Common names: lantana

Lantana camara -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
June 23, 2016
Evaluation Time (hrs): 
2 Hours
Evaluation Status: 
Completed
Plant Information
Plant Material: 
If the plant is a cultivar, and if the cultivar's behavior differs from its parent's (behavior), explain how: 
Regional Information
Region Name: 
Climate Matching Map
These maps were built using a toolkit created in collaboration between GreenInfo Network, PlantRight, Cal-IPC, and Agricultural Sustainability Institute at UC Davis.
Climate Matching Maps PDF: 
Invasive History and Climate Matching
1. Has the species (or cultivar or variety, if applicable; applies to subsequent "species" questions) become naturalized where it is not native?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Naturalized in California. Present in 10 counties according to Calflora. Native of Caribbean, Central and South America, but naturalized in neotropical and subtropical regions of the world. There are many points in GBIF.
Reference(s): 
2. Is the species (or cultivar or variety) noted as being naturalized in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Very High
Answer / Justification: 
Naturalized in California. Present in 10 counties according to Calflora. Native of Caribbean, Central and South America, but naturalized in neotropical and subtropical regions of the world. There are many points in GBIF, including areas of South Africa, Australia, China and Europe that are similar to California.
3. Is the species (or cultivar or variety) noted as being invasive in the U.S. or world?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Very High
Answer / Justification: 
L. camara is generally deleterious to biodiversity and human activities and has been the target of control programs for a century; however, successful control has only been achieved in a few instances using biocontrol agents. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures (CABI Invasive Species Compendium). L. camara is considered invasive in Florida, Hawaii, New Caledonia, Australia and New Zealand. Note from Ron Vanderhoff: it should be noted that in California I cannot find any specific evidence of documented invasive behavior for this species. I carefully reviewed all 40 Calflora records (which includes all georeferenced CCH records). I read the individual location descriptions and the comments for each record and viewed an aerial map (where the location accuracy is high). In summary, there is no record that appears to indicate invasiveness. The majority of the records reference individual plants, mention roadsides or disturbed areas or mention landscaping. This does not discount any of the scores contained in this review and does not discount invasiveness in other areas of the world. In conclusion, it does not appear that this species is (yet) exhibiting invasiveness in California.
Reference(s): 
4. Is the species (or cultivar or variety) noted as being invasive in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
3
Confidence Level: 
Very High
Answer / Justification: 
L. camara is generally deleterious to biodiversity and human activities and has been the target of control programs for a century; however, successful control has only been achieved in a few instances using biocontrol agents. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures (CABI Invasive Species Compendium). There are many points in GBIF, including areas of South Africa, Australia, China and Europe that are similar to California.
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Lantana montevidensis is also naturalized in California and occurs in a few of the climate areas which match California: Southern Europe, Australia and New Zealand. It is also considered invasive in Florida, Hawaii, New Caledonia, Australia and New Zealand.
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Based on locations in GBIF and description in CABI, it occurs mostly in areas that are more tropical than California. Map: http://www.gbif.org/species/2925303
Impact on Native Plants and Animals
7. Does this plant displace native plants and dominate (overtop or smother) the plant community in areas where it has established?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
In natural and semi-natural vegetation L. camara may smother vegetation and increase fire intensity (due to an increase in dry biomass), thus displacing native scrub communities. "Its allelopathic qualities can reduce vigour of nearby plant species and reduce productivity in orchards" http://www.iucngisd.org/gisd/species.php?sc=56
Reference(s): 
8. Is the plant noted as promoting fire and/or changing fire regimes?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
In natural and semi-natural vegetation L. camara may smother vegetation and increase fire intensity (due to an increase in dry biomass), thus displacing native scrub communities.
Reference(s): 
9. Is the plant a health risk to humans or animals/fish? Has the species been noted as impacting grazing systems?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
The alkaloid-rich leaves of L. camara are virtually immune to grazing by livestock, so in areas where it dominates the vegetation it could alter grazing regimes. When ingested by cattle and sheep it may cause photosensitive reactions, diarrhoea, jaundice, hepatitis and poisoning. Children have been known to die after eating unripe berries.
Reference(s): 
10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Stands of L. camara, and of the prickly variety in particular, hinder human access to invaded habitats. It forms extensive, dense and impenetrable thickets in forestry plantations, orchards, pasture land, waste land and in natural areas.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
L. camara is able to produce adventitious shoots, especially shallow lateral roots, following mechanical damage. Hence, it is also able to spread and establish dense thickets by vegetative means. The capacity of the species to spread vegetatively and to inhibit both the growth of other vegetation and seed germination, in conjunction with heavy and regular fruiting, is the main reason why L. camara forms long-lasting permanent thickets. Additional references to L. camara reproducing vegetatively are in Vardien (2012) for South Africa and in a fact sheet prepared by the Queensland Government: https://www.daf.qld.gov.au/__data/assets/pdf_file/0009/62010/IPA-Lantana-PP34.pdf
Reference(s): 
12. If naturally detached fragments from this plant are capable of producing new plants, is this a common method of reproduction for the plant?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Existing colonies may also spread laterally via the production of suckers or when branches take root after coming into contact with the soil (i.e. by layering). Stem fragments or pieces of the rootstock (i.e. crown) can also give rise to new plants after being moved by machinery or dumped in garden waste.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Heavy fruit crops are produced yearly. Seeds germinate when sufficient moisture is available, usually at the start of a rainy season.
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
A single plant can produce up to 12,000 seeds per year.
Reference(s): 
15. Is there significant germination (>25%) of seeds the next growing season, with no requirement of an infrequent environmental condition for seeds to germinate (i.e. fire) or long dormancy period?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
Seed dormancy was initially high, but dropped significantly in the first 6 months with steady declines thereafter. This suggests that dormancy of lantana seeds is largely exogenous, with primary dormancy breaking down quickly. Results indicated that under field conditions one would expect seedling emergence percentages to be low (25% or less) and that emergence from a single cohort may continue for 3 yr or longer under fairly typical field conditions. However, seedling emergence could be considerably greater where the soil remains moist for extended periods. Comment from Ron Vanderhoff: I see a few published references to poor seed germination for this species. A notable study (Wijayabandara et al 2013) suggests that the seed had almost zero germination without assistance from ingestion by birds. In the same study, cold stratification is suggested, but was not tested. Germination rates appear to be quite low in this species, suggesting that this PRE score may be too high.
Reference(s): 
16. Does this plant produce viable seed within the first three years (for an herbaceous species) to five years (for a woody species) after germination?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Plants mature and produce seeds in one year and are long-lived and drought tolerant once established.
Reference(s): 
17. Does this plant continuously produce seed for >3 months each year or does seed production occur more than once a year?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Flowering and fruiting take place throughout the year with a peak during the first 2 months of the rainy season. Germination across the range of temperatures tested indicated that lantana germination can occur at any time of the year in a subtropical environment (Vivian-Smith 2009).
Reference(s): 
Dispersal
18. Are the plant’s propagules frequently dispersed long distance (>100 m) by mammals or birds or via domestic animals?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
A number of bird species, and also sheep and goats disperse the seeds, sometimes over long distances.
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Occasionally abiotic seed dispersal may occur. Flash floods in South Africa, caused by cyclone Demoina in 1983, transported seeds and deposited them on the flood plain of the Ndumu game reserve. In Kruger National Park L. camara has spread primarily along rivers (Vardien 2012).
Reference(s): 
20. Are the plant’s propagules frequently dispersed via contaminated seed (agriculture or wildflower packets), equipment, vehicles, boats or clothing/shoes?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Seeds are dispersed over long distances by birds and mammals, as well as through horticulture.
Reference(s): 
Evaluation Notes

GBIF: http://www.gbif.org/species/2925303

CABI datasheet: http://www.cabi.org/isc/datasheet/29771

Queensland: http://keyserver.lucidcentral.org/weeds/data/media/Html/lantana_camara.htm

Queensland Fact Sheet: https://www.daf.qld.gov.au/__data/assets/pdf_file/0009/62010/IPA-Lantana...

PIER: http://www.hear.org/pier/species/lantana_camara.htm

Sunset Western Garden Book

Reviewed by Ron Vanderhoff, Naomi Fraga and Gina Darin.

Comment from Ron Vanderhoff on L. camara invasiveness in California: it should be noted that in California I cannot find any specific evidence of documented invasive behavior for this species. I carefully reviewed all 40 Calflora records (which includes all georeferenced CCH records). I read the individual location descriptions and the comments for each record and viewed an aerial map (where the location accuracy is high). In summary, there is no record that appears to indicate invasiveness. The majority of the records reference individual plants, mention roadsides or disturbed areas or mention landscaping. This does not discount any of the scores contained in this review and does not discount invasiveness in other areas of the world. In conclusion, it does not appear that this species is (yet) exhibiting invasiveness in California.

 

Total PRE Score

  • < 13 : accept (low risk of invasiveness)
  • 13 - 15 : evaluate further
  • > 15 : reject (high risk of invasiveness)

PRE Score: 
22
Number of questions answered: 
20
Screener Confidence (%): 
90.0
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Evaluation visibility: 
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