Australia/New Zealand Weed Risk Assessment adapted for Florida. Data used for analysis published in: Gordon, D.R., D.A. Onderdonk, A.M. Fox, R.K. Stocker, and C. Gantz. 28. Predicting Invasive Plants in Florida using the Australian Weed Risk Assessment. Invasive Plant Science and Management : 78-95. Agave americana (century plant) Question number Question Answer Score. Is the species highly domesticated? n.2 Has the species become naturalised where grown?.3 Does the species have weedy races? 2. Species suited to Florida's USDA climate zones (-low; - 2 intermediate; 2-high) 2.2 Quality of climate match data (-low; -intermediate; 2-high) 2 2.3 Broad climate suitability (environmental versatility) 2.4 Native or naturalized in habitats with periodic inundation n? 2.5 Does the species have a history of repeated introductions outside y its natural range? 3. Naturalized beyond native range y 3.2 Garden/amenity/disturbance weed n 3.3 Weed of agriculture y 3.4 Environmental weed y 3.5 Congeneric weed y 4. Produces spines, thorns or burrs y 4.2 Allelopathic n 4.3 Parasitic n 4.4 Unpalatable to grazing animals? 4.5 Toxic to animals n 4.6 Host for recognised pests and pathogens 4.7 Causes allergies or is otherwise toxic to humans y 4.8 Creates a fire hazard in natural ecosystems n 4.9 Is a shade tolerant plant at some stage of its life cycle n 4. Grows on infertile soils (oligotrophic, limerock, or excessively y draining soils) 4. Climbing or smothering growth habit n 4.2 Forms dense thickets y 5. Aquatic n 5.2 Grass n 5.3 Nitrogen fixing woody plant n 5.4 Geophyte n 6. Evidence of substantial reproductive failure in native habitat 6.2 Produces viable seed y
6.3 Hybridizes naturally y 6.4 Self-compatible or apomictic 6.5 Requires specialist pollinators? 6.6 Reproduction by vegetative fragmentation y 6.7 Minimum generative time (years) 7. Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) 7.2 Propagules dispersed intentionally by people y 7.3 Propagules likely to disperse as a produce contaminant n - 7.4 Propagules adapted to wind dispersal n - 7.5 Propagules water dispersed n 7.6 Propagules bird dispersed 7.7 Propagules dispersed by other animals (externally) n - 7.8 Propagules dispersed by other animals (internally) 8. Prolific seed production n - 8.2 Evidence that a persistent propagule bank is formed (> yr) 8.3 Well controlled by herbicides y - 8.4 Tolerates, or benefits from, mutilation or cultivation 8.5 Effective natural enemies present in Florida, or east of the continental divide Total Score 4 - Outcome Reject* *Used secondary screen from: Daehler, C. C., J.L. Denslow, S. Ansari, and H. Kuo. 24. A risk assessment system for screening out harmful invasive pest plants from Hawaii s and other Pacific islands. Conserv. Biol. 8: 36-368. section # questions answered satisfy minimum? A 7 yes B yes C 4 yes total 3 yes Data collected 26-27 2
Question number Reference Source data. cultivated, but no evidence of selection for reduced weediness.2.3 2. 2.2 2.3 2.4 Dehgan (998) Landscape Plants for Subtropical native to arid regions of Mexico 2.5 Whistler (2) Tropical Ornamentals: a Guide. Timber Press, Portland. "widely cultivated for its attractive foliage and as a novelty" 3.. Harden (993) Flora of New South Wales. New South Wales University Press. 2. Badano and Pugnaire (24) Invasion of Agave species (Agavaceae) in south-east Spain: invader demographic parameters and impacts on native species. Diversity and Distributions : 493-5. 3. Richardson, Macdonald, Hoffman, and Henderson (997) Alien plant invasions. Pp. 535-57 in Cowling, Richardson, and Pierce University Press. 4. Waterhouse (997) The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. ACIAR Monograph No. 44, 99p. Naturalized in Australia (), Spain (2), southern Africa (3), and the Pacific (4) 3.2 no evidence 3.3 Waterhouse (997) The major invertebrate pests and weeds of agriculture and plantation forestry considered a major weed of in the southern and western Pacific. ACIAR agriculture in the southern and Monograph No. 44, 99p. western Pacific (table ) 3.4. Badano and Pugnaire (24) Invasion of Agave species (Agavaceae) in south-east Spain: invader demographic parameters and impacts on native species. Diversity and Distributions : 493-5. 2. Richardson, Macdonald, Hoffman, and Henderson (997) Alien plant invasions. Pp. 535-57 in Cowling, Richardson, and Pierce University Press. 3.5 Richardson, Macdonald, Hoffman, and Henderson (997) Alien plant invasions. Pp. 535-57 in Cowling, Richardson, and Pierce University Press. 4. Dehgan (998) Landscape Plants for Subtropical 4.2 USDA, NRCS. 25. The PLANTS Database, Version Data Center, Baton Rouge, LA 7874-449 USA.. Agave americana is spreading in coastal dunes in Spain, "interfering with the dominant native species". 2. Agave americana considered one of 84 important environmental weeds in southern African biomes (Appendix 22.). A. sisalana also considered one of 84 important environmental weeds in southern African biomes. "leaves are fibrous with a sharp terminal black spine; often have sharp marginal teeth" not allelopathic 3
4.3 Dehgan (998) Landscape Plants for Subtropical no description of this 4.4 "Agaves are consumed by both Nobel (988) Environmental biology of agaves wild and domesticated animals in and cacti. Cambridge University Press, arid and semiarid regions." [unclear Cambridge. whether eaten readily] 4.5 USDA, NRCS. 25. The PLANTS Database, Version Data Center, Baton Rouge, LA 7874-449 USA. no toxicity 4.6 4.7 causes dermatitis in humans 4.8 no evidence 4.9. USDA, NRCS. 25. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 7874-449 USA. 2. Dehgan (998) Landscape Plants for Subtropical 4.. Badano and Pugnaire (24) Invasion of Agave species (Agavaceae) in south-east Spain: invader demographic parameters and impacts on native species. Diversity and Distributions : 493-5. 2. Dehgan (998) Landscape Plants for Subtropical Climates. University Press of Florida.. shade intolerant 2. plant in full sun. "This suggests that sandy soils are an opportunity which releases the clonal reproduction of Agave [including A. americana]." 2. "tolerates poor sandy soil" 4. Dehgan (998) Landscape Plants for Subtropical "rosulate shrub" 4.2 "A single individual can form dense Weber (23) Invasive Plant Species of the World. CABI Publishing. impenetrable stands that eliminate native vegetation." 5. terrestrial 5.2 USDA, NRCS. 25. The PLANTS Database, Version Data Center, Baton Rouge, LA 7874-449 USA. Agavaceae 5.3 USDA, NRCS. 25. The PLANTS Database, Version Data Center, Baton Rouge, LA 7874-449 USA. not nitrogen fixing (and Agavaceae) 5.4. USDA, NRCS. 25. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 7874-449 USA. 2. Horticopia 4. 6. 6.2 Gentry (982) Agaves of Continental North America. 6.3 6.4 Gentry (982) Agaves of Continental North America.. not propagated by bulbs, corms, or tubers 2. "This plant's roots are fibrous." "...freely suckering and sometimes seeding" Morphological intermediates between A. americana and A. scabra have been observed along the eastern edges of the Chihuahuan or Coahuilan Desert, "seeming to express interspecific hybrids". 4
6.5 Gentry (982) Agaves of Continental North America. 6.6. Gentry (982) Agaves of Continental North America. 2. Badano and Pugnaire (24) Invasion of Agave species (Agavaceae) in south-east Spain: invader demographic parameters and impacts on native species. Diversity and Distributions : 493-5. 6.7 7. 7.2 Whistler (2) Tropical Ornamentals: a Guide. Timber Press, Portland.. Gentry (982) Agaves of Continental North America. 2. Nobel (988) Environmental biology of agaves and cacti. Cambridge University Press, Cambridge. Bats are important pollinators of agaves, and agave flowers are also visited by hummingbirds, other birds, and insects. [primary pollinators are specialists]. "...freely suckering and sometimes seeding" 2. " showing that rhizomes are the main propagation mechanisms of A. americana in this site" "flowers infrequently, after 5 to 3 years of growth" [but time to vegetative reproduction is not known]. In Mesoamerica and elsewhere, agaves are widely cultivated for food, drink, and fiber. 2. Agave americana is used throughout the world as an ornamental. 7.3 no evidence 7.4 Dehgan (998) Landscape Plants for Subtropical seeds germinate on plant and then fall to the ground and root 7.5 no evidence 7.6 7.7 no evidence that fruit has any means of attachment 7.8 8.. USDA, NRCS. 25. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 7874-449 USA. 2. Whistler (2) Tropical Ornamentals: a Guide. Timber Press, Portland. 8.2 8.3 Tunison and Zimmer (992) Success in controlling localized alien plants in Hawaii Volcanoes National Park. Pp. 56-524 in Stone, Smith, and Tunison (eds.) Alien Plant Invasions in Native Ecosystems of Hawaii: Management and Research. University of Hawaii Press, Honolulu. 8.4 8.5. fruit/seed abundance: low 2. "flowers infrequently, after 5 to 3 years of growth it dies after flowering" Application of 5% Garlon 4 to A. americana plants in Hawaii Volcanoes National Park resulted in a reduction from 25 to 5 plants after 2 years. 5