Tibouchina herbacea risk assessment

Pacific Island Ecosystems at Risk (PIER)

Tibouchina herbacea

RISK ASSESSMENT RESULTS: High risk, score: 24

Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

	Tibouchina herbacea (cane ti, cane tibouchina, glorybush, tibouchina, tibouchinati ) Synonym: Arthrostemma herbacea DC. (basionym) Family - Melastomaceae	Answer	Score
1.01	Is the species highly domesticated? (If answer is 'no' then go to question 2.01)	n	0
1.02	Has the species become naturalized where grown?
1.03	Does the species have weedy races?
2.01	Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”	2
2.02	Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2	2
2.03	Broad climate suitability (environmental versatility)	n	0
2.04	Native or naturalized in regions with tropical or subtropical climates	y	1
2.05	Does the species have a history of repeated introductions outside its natural range? y=-2	n
3.01	Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05	y	2
3.02	Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)	y
3.03	Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)	y	4
3.04	Environmental weed y = 2*multiplier (see Append 2)	y	4
3.05	Congeneric weed y = 1*multiplier (see Append 2)	y	2
4.01	Produces spines, thorns or burrs	n	0
4.02	Allelopathic	n	0
4.03	Parasitic	n	0
4.04	Unpalatable to grazing animals	y	1
4.05	Toxic to animals	n	0
4.06	Host for recognized pests and pathogens	n	0
4.07	Causes allergies or is otherwise toxic to humans	n	0
4.08	Creates a fire hazard in natural ecosystems	n	0
4.09	Is a shade tolerant plant at some stage of its life cycle	y	1
4.1	Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)	y	1
4.11	Climbing or smothering growth habit	n	0
4.12	Forms dense thickets	y	1
5.01	Aquatic	n	0
5.02	Grass	n	0
5.03	Nitrogen fixing woody plant	n	0
5.04	Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)	n	0
6.01	Evidence of substantial reproductive failure in native habitat	n	0
6.02	Produces viable seed.	y	1
6.03	Hybridizes naturally
6.04	Self-compatible or apomictic	y	1
6.05	Requires specialist pollinators	n	0
6.06	Reproduction by vegetative fragmentation	y	1
6.07	Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1	2	0
7.01	Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)	y	1
7.02	Propagules dispersed intentionally by people	y	1
7.03	Propagules likely to disperse as a produce contaminant	n	-1
7.04	Propagules adapted to wind dispersal	n	-1
7.05	Propagules water dispersed	n	-1
7.06	Propagules bird dispersed	y	1
7.07	Propagules dispersed by other animals (externally)	n	-1
7.08	Propagules survive passage through the gut	y	1
8.01	Prolific seed production (>1000/m2)	y	1
8.02	Evidence that a persistent propagule bank is formed (>1 yr)	y	1
8.03	Well controlled by herbicides	n	1
8.04	Tolerates, or benefits from, mutilation, cultivation, or fire	y	1
8.05	Effective natural enemies present locally (e.g. introduced biocontrol agents)
	Total score:		24

Supporting data:

	Notes	Reference
1.01	No evidence
1.02
1.03
2.01	(1)"Native range: Southern Brazil, Uruguay and Paraguay ." (2)"Native: SOUTHERN AMERICA Brazil: Brazil Southern South America: Argentina; Paraguay; Uruguay"	(1)http://www.hear.org/pier/species/tibouchina_herbacea.htm (2)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl
2.02
2.03	(1)majority of the specimens collected from South American range were below 500 m except one from Bolivia at around 3300 m. (2)In Hawaii inhabits wet habitats above 1000 m on the Island of Hawaii - "Altitude at the study site ranges from 518 to 1232 m."	(1)http://mobot.mobot.org/cgi-bin/search_vast (2)Kama N. Almasi. 2000. A Non-native Perennial Invades a Native Forest. Biological Invasions. 2(3): 219-230.
2.04	(1)"Native range: Southern Brazil, Uruguay and Paraguay ." (2)"Native: SOUTHERN AMERICA Brazil: Brazil Southern South America: Argentina; Paraguay; Uruguay"	(1)http://www.hear.org/pier/species/tibouchina_herbacea.htm (2)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl
2.05	"In Hawai‘i, "naturalized and locally abundant in disturbed mesic to wet forest." [No evidence of it being introduced elsewhere other than Hawaii].	http://www.hear.org/pier/species/tibouchina_herbacea.htm
3.01	"In Hawai‘i, "naturalized and locally abundant in disturbed mesic to wet forest."	http://www.hear.org/pier/species/tibouchina_herbacea.htm
3.02	"A non-native perennial sub-shrub, T. herbacea is invading both disturbed, open canopy sites and closed canopy wet native forests of Hawaii and Maui. … it appears to become established both in areas of high anthropogenic disturbance and natural areas." [This question not scored because it is scored for invasiveness under 3.04]	Kama N. Almasi. 2000. A Non-native Perennial Invades a Native Forest. Biological Invasions. 2(3): 219-230.
3.03	State Noxious Weed Lists for 46 States. State agriculture or natural resource departments.	http://plants.usda.gov/java/profile?symbol=TIHE2
3.04	"It forms dense monotypic stands over 3 m tall, clogging waterways and infesting wet, upland pastures and rainforest. … difficult to germinate because they require continuously moist conditions. Once established however the plant forms dense, monotypic thickets."	http://www.invasive.org/publications/xsymposium/proceed/08pg639.pdf
3.05	Tibouchina urvilleana - "Very invasive in Hawai‘i. On list of plants to be excluded from French Polynesia. Isolated specimens seen near the top of the cross-island road, Upolu, Samoa. One location on Rarotonga, Cook Islands."	http://www.hear.org/Pier/species/tibouchina_urvilleana.htm
4.01	No evidence of such structures.	http://www.hear.org/pier/species/tibouchina_herbacea.htm
4.02	No evidence
4.03	No evidence
4.04	"Cattle will not eat it."	http://www.invasive.org/publications/xsymposium/proceed/08pg639.pdf
4.05	No evidence
4.06	In the native range - "A number of insects attack the plant including Schrenkensteinia sp. (Lepidoptera: Schrenkensteinidae), Syphrea uberabensis (Col.: Chrysomelidae: Alticinae), Anthonomusopius and A. partiarius (Col.: Curculionidae: Sibinae), Lius sp. (Col.: Chrysomelidae:Alticinae). Studies with the Schrenkensteinia are the most advanced. It is a leaf-skele-tonizer that only attacks herbaceous Tibouchina species. It is, however, very susceptibleto Beauveria. It may not be suitable for biological control in Hawaii due to the presenceof several generalist lepidopteran parasitoids. There is also a large, undescribed geometridwhose larvae mimic the stems, either purple or green. It is a voracious defoliator." [No evidence that the above are economic pests].
4.07