Pacific Island Ecosystems at Risk (PIER)
RISK ASSESSMENT RESULTS: High risk, score: 11
|
Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service Information on
Risk Assessments |
Thunbergia grandiflora Roxb. (Bengal clock vine, Bengal trumpet, blue skyflower, blue trumpet vine) synonyms: T. lacei and T. clarkei |
Answer |
||
1.01 |
Is the species highly domesticated? |
y=-3, n=0 |
n |
1.02 |
Has the species become naturalized where grown? |
y=-1, n=-1 |
y |
1.03 |
Does the species have weedy races? |
y=-1, n=-1 |
n |
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” |
See Append 2 |
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) |
y=1, n=0 |
y |
2.04 |
Native or naturalized in regions with tropical or subtropical climates |
y=1, n=0 |
y |
2.05 |
Does the species have a history of repeated introductions outside its natural range? y=-2 |
?=-1, n=0 |
y |
3.01 |
Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05 |
y |
|
3.02 |
Garden/amenity/disturbance weed y = 1*multiplier (see Append 2) |
n=0 |
n |
3.03 |
Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2) |
n=0 |
n |
3.04 |
Environmental weed y = 2*multiplier (see Append 2) |
n=0 |
y |
3.05 |
Congeneric weed y = 1*multiplier (see Append 2) |
n=0 |
y |
4.01 |
Produces spines, thorns or burrs |
y=1, n=0 |
n |
4.02 |
Allelopathic |
y=1, n=0 |
n |
4.03 |
Parasitic |
y=1, n=0 |
n |
4.04 |
Unpalatable to grazing animals |
y=1, n=-1 |
|
4.05 |
Toxic to animals |
y=1, n=0 |
n |
4.06 |
Host for recognized pests and pathogens |
y=1, n=0 |
n |
4.07 |
Causes allergies or is otherwise toxic to humans |
y=1, n=0 |
n |
4.08 |
Creates a fire hazard in natural ecosystems |
y=1, n=0 |
n |
4.09 |
Is a shade tolerant plant at some stage of its life cycle |
y=1, n=0 |
y |
4.1 |
Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) |
y=1, n=0 |
y |
4.11 |
Climbing or smothering growth habit |
y=1, n=0 |
y |
4.12 |
Forms dense thickets |
y=1, n=0 |
n |
5.01 |
Aquatic |
y=5, n=0 |
n |
5.02 |
Grass |
y=1, n=0 |
n |
5.03 |
Nitrogen fixing woody plant |
y=1, n=0 |
n |
5.04 |
Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) |
y=1, n=0 |
y |
6.01 |
Evidence of substantial reproductive failure in native habitat |
y=1, n=0 |
n |
6.02 |
Produces viable seed. |
y=1, n=-1 |
y |
6.03 |
Hybridizes naturally |
y=1, n=-1 |
|
6.04 |
Self-compatible or apomictic |
y=1, n=-1 |
|
6.05 |
Requires specialist pollinators |
y=-1, n=0 |
y |
6.06 |
Reproduction by vegetative fragmentation |
y=1, n=-1 |
y |
6.07 |
Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 |
See left |
2 |
7.01 |
Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) |
y=1, n=-1 |
y |
7.02 |
Propagules dispersed intentionally by people |
y=1, n=-1 |
y |
7.03 |
Propagules likely to disperse as a produce contaminant |
y=1, n=-1 |
n |
7.04 |
Propagules adapted to wind dispersal |
y=1, n=-1 |
|
7.05 |
Propagules water dispersed |
y=1, n=-1 |
n |
7.06 |
Propagules bird dispersed |
y=1, n=-1 |
n |
7.07 |
Propagules dispersed by other animals (externally) |
y=1, n=-1 |
n |
7.08 |
Propagules survive passage through the gut |
y=1, n=-1 |
n |
8.01 |
Prolific seed production (>1000/m2) |
y=1, n=-1 |
n |
8.02 |
Evidence that a persistent propagule bank is formed (>1 yr) |
y=1, n=-1 |
|
8.03 |
Well controlled by herbicides |
y=-1, n=1 |
y |
8.04 |
Tolerates, or benefits from, mutilation, cultivation, or fire |
y=1, n=-1 |
y |
8.05 |
Effective natural enemies present locally (e.g. introduced biocontrol agents) |
y=-1, n=1 |
|
Total score: |
11 |
Supporting data:
Notes |
Source |
|
1.01 |
no evidence |
|
1.02 |
Distributional range: |
USDA, ARS, National Genetic Resources Program. |
1.03 |
no evidence |
|
2.01 |
Distributional range: |
USDA, ARS, National Genetic Resources Program. |
2.02 |
||
2.03 |
(1)Hardiness Range 9B to 11 (2)rainforest habitat (3)Specimens from sea level to 1600 m (4)This Thunbergia species does very well in the Coastal region of South Carolina and has survived temperatures as low as 15 F. |
(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://farrer.riv.csu.edu.au/ASGAP/APOL16/dec99-2.html (3)http://mobot.mobot.org/cgi-bin/search_vast (4)http://davesgarden.com/pdb/go/1968/index.html |
2.04 |
Distributional range: |
USDA, ARS, National Genetic Resources Program. |
2.05 |
Distribution in US: Florida, Hawaii, Puerto Rico |
USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. |
3.01 |
Distributional range: Native: ASIA-TROPICAL Indian Subcontinent: Bhutan; India [n.e.]; Nepal Indo-China: Myanmar Other: cultivated & sometimes naturalized elsewhere |
USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Thunbergia+grandiflora (11 September 2004) |
3.02 |
no evidence |
|
3.03 |
no evidence |
|
3.04 |
(1)"Thunbergia (Thunbergia grandiflora) is destroying north Queensland tropical lowland rain forests at a rate of about 0.5 ha/yr. " (2)Significant environmental weed of Queensland and Northern Territory (Australia) |
(1)Haaren, P. van , Vitelli, J. (1997) Chemical control of thunbergia (Thunbergia grandiflora). Plant Protection Quarterly, 1997, Vol. 12, No. 1, pp. 29-32, 11 ref. (2)RANDALL, R. 2001. Garden thugs, a national list of invasive and potentially invasive garden plants. Plant Protection Quarterly 16: 138-171. |
3.05 |
Thunbergia alata are T. annua are listed as common and pricipal weeds. |
Bacon, P., P.J. Terry, N. Waltham, & P.Castro S. (1997) An Electronic Atlas of World Weed and Invasive Plants. Version 1.0, 1997. A database based on the original work "A Geographical Atlas of World Weeds" by Holm et al 1979. |
4.01 |
no description of these traits |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
4.02 |
no evidence |
|
4.03 |
no evidence |
|
4.04 |
don't know |
|
4.05 |
no evidence |
|
4.06 |
no evidence |
|
4.07 |
no evidence |
|
4.08 |
rainforest plant |
http://farrer.riv.csu.edu.au/ASGAP/APOL16/dec99-2.html |
4.09 |
(1)Exposure: Partial shade or partial sun to full sun (2)It is one of the most free flowering vines for shade (3)mine is flowering inside [can be grown indoors] |
(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://davesgarden.com/pdb/go/1968/index.html (3)http://davesgarden.com/pdb/go/1968/index.html |
4.1 |
Soil Condition Loamy, sandy, clay, acidic, neutral, alkaline, tolerates salt, somewhat drought tolerant |
Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. |
4.11 |
"Habitat/ecology: Climbing vine. Can smother individual and groups of trees." |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
4.12 |
vine |
|
5.01 |
vine; Acanthaceae |
|
5.02 |
vine; Acanthaceae |
|
5.03 |
vine; Acanthaceae |
|
5.04 |
vine with tuber |
|
6.01 |
invade native habitat |
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP23.pdf |
6.02 |
"Propagation: Seeds, cuttings, and fragments of stems and roots. Cultivated as an ornamental and most commonly spread from dumping of garden cuttings." |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
6.03 |
no evidence |
|
6.04 |
failed to set seed, possibly because the vines were descended from a single self-incompatible variety |
Young, A. M. (1983) Nectar and pollen robbing of Thunbergia grandiflora by Trigona bees in Costa Rica. Biotropica, 1983, Vol. 15, No. 1, pp. 78-80 |
6.05 |
(1) AB: "The flowers were visited by the bee Xylocopa
latipes; in Thailand another Xylocopa sp. also visited them. The bee has to
push through a narrow channel between the stamens to reach the nectar. No
nectar robbing was observed, even when ants were excluded. Thus, the results
do not support the hypothesis that ants protect flowers from nectar
robbing." [Xylocopa species] |
(1) Fiala, B. , Krebs, A. , Barlow, H. S. , Maschwitz, U.
(1996) Interactions between the climber Thunbergia grandiflora, its
pollinator Xylocopa latipes and the ant Dolichoderus thoracicus: the
"nectar-thief hypothesis" refuted? Malayan Nature Journal, 1996, Vol. 50,
No. 1, pp. 1-14 |
6.06 |
"Propagation: Seeds, cuttings, and fragments of stems and roots. Cultivated as an ornamental and most commonly spread from dumping of garden cuttings." |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
6.07 |
flowers in first year [after purchasing at a garden shop, so total time >1 year] |
http://davesgarden.com/pdb/go/1968/index.html |
7.01 |
"Propagation: Seeds, cuttings, and fragments of stems and roots. Cultivated as an ornamental and most commonly spread from dumping of garden cuttings." |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
7.02 |
"Propagation: Seeds, cuttings, and fragments of stems and roots. Cultivated as an ornamental and most commonly spread from dumping of garden cuttings." |
http://www.hear.org/pier/species/thunbergia_grandiflora.htm |
7.03 |
no evidence |
|
7.04 |
The seed pod is inconspicuous, cone shaped, 3-5 cm long, with a rounded base. The seed is flat, up to 1 cm long and covered with brown scales. It is catapulted several metres when the ripe pod splits. [not described as wind-dispersed, but seed is flat; don't know if it is winged] |
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP23.pdf |
7.05 |
no evidence |
|
7.06 |
The seed pod is inconspicuous, cone shaped, 3-5 cm long, with a rounded base. The seed is flat, up to 1 cm long and covered with brown scales. It is catapulted several metres when the ripe pod splits. |
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP23.pdf |
7.07 |
The seed pod is inconspicuous, cone shaped, 3-5 cm long, with a rounded base. The seed is flat, up to 1 cm long and covered with brown scales. It is catapulted several metres when the ripe pod splits. |
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP23.pdf |
7.08 |
no evidence of ingestion |
|
8.01 |
The seed pod is inconspicuous, cone shaped, 3-5 cm long, with a rounded base. The seed is flat, up to 1 cm long and covered with brown scales. It is catapulted several metres when the ripe pod splits. [probably not, lare seed; generally no seeds produced from cultivated plants] |
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP23.pdf |
8.02 |
no evidence |
|
8.03 |
(1) AB: Three experiments were conducted near Innisfail,
Queensland, during 1987-91, to test 25 herbicides at various concentrations
as high volume foliar applications for the control of thunbergia. Most
herbicides produced 100% brown out, but failed to prevent regrowth of
underground tubers and allowed complete recovery of treated plants in 3-6
months. Only imazapyr (1.87, 2.5 and 3.75 g L-1) killed both the
above-ground growth and the tuberous root system. The three next most
effective herbicides, triclopyr/picloram, fluroxypyr and 2,4-D/picloram
produced 80-100% foliage reduction and 20-75% regrowth of underground
tubers. [depends on the herbicides used] |
(1) Haaren, P. van , Vitelli, J. (1997) Chemical control of
thunbergia (Thunbergia grandiflora). Plant Protection Quarterly, 1997, Vol.
12, No. 1, pp. 29-32, 11 ref. |
8.04 |
(1) "Regular pruning is required to keep this plant in
bounds." [tolerate heavy pruning] |
(1) http://hort.ifas.ufl.edu/shrubs/THUGRAA.PDF |
8.05 |
no evidence |
Need more info? Have questions? Comments? Information to contribute? Contact PIER!
[ Return to PIER homepage ] [Risk assessment page]
This page new 31 January 2004.