Pacific Island Ecosystems at Risk (PIER)


Tecoma stans


RISK ASSESSMENT RESULTS: High risk, score: 8


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
Original risk assessment

Tecoma stans (yellow bells)

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

y

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

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

n

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

n

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

n

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

n

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

3

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

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

y

7.05

Propagules water dispersed

y=1, n=-1

y

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

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

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

8

Supporting data:

Source

Notes

1.01

Did not find any evidence of the species being a cultivar.

1.02

(1) 'The plant is native of tropical America, planted and grown in many tropical countries … .' Naturalized on Christmas Island, (2) French Polynesia, South Africa, Australia

(1) Bose, T. K., Das, P and Maiti G. G. 1998. Trees of the world. Regional plant resource center. Bhubaneshwar, India. (2) http://www.hear.org/pier3/testa.htm

1.03

Although there are 3 other known varieties of this species - there is no evidence that these are weedy.

2.01

(1) 'The plant is native of tropical America, planted and grown in many tropical countries … .' official flower of the U.S. Virgin Islands. Naturalized on Christmas Island, (2) Micronesia and (3) American Samoa.

(1) Bose, T. K., Das, P and Maiti G. G. 1998. Trees of the world. Regional plant resource center. Bhubaneshwar, India. (2) http://www.hear.org/pier/mappendix2.htm#Table3 (3) http://www.hear.org/pier/asappendix2.htm#Table2

2.02

2.03

It can grow upto an elevation of 1500 m. 2)USDA zones 7-11

Prakash, E. O. and Rao, J. T. Asian journal of chemistry. 1999. Vol 11(1): 240 2)http://www.floridata.com/ref/t/teco_sta.cfm

2.04

(1) 'The plant is native of tropical America, planted and grown in many tropical countries … .' Naturalized on Christmas Island, (2) Micronesia and (3) American Samoa.

(1) Bose, T. K., Das, P and Maiti G. G. 1998. Trees of the world. Regional plant resource center. Bhubaneshwar, India. (2) http://www.hear.org/pier/mappendix2.htm#Table3 (3) http://www.hear.org/pier/asappendix2.htm#Table2

2.05

Has been introduced widely for horticulture

See above references.

3.01

(1) It is a pest species on Christmas Island and (2) weedy in Micronesia (3) weedy in American Samoa and elsewhere

(1) Swarbrick, J. T. & R. Hart. 2001. Environmental weeds of Christmas Island (Indian Ocean) and their management. Plant Protection Quaterly. Vol 16: (2): 54-57. (2) http://www.hear.org/pier/mappendix2.htm#Table3 (3) http://www.hear.org/pier/asappendix2.htm#Table2

3.02

No evidence .

3.03

No evidence of it being a weed of agriculture, forestry or horticulture.

3.04

(1) It is a major environmental weed on Christmas island. (2) It is a weed in the pastures of Brazil too with 10,000 hectares seriously affected. (3) A very serious invasive species in French Polynesia. Now part of the flora to as high as 2,500 feet in elevation,
and perhaps higher (Setchell, quoted in Welsh, 1998) 4) Category 1 environmental weed in South Africa. 5)Proposed W2 Category Noxious Weed in Australia

(1) Swarbrick, J. T. & R. Hart. 2001. Environmental weeds of Christmas Island (Indian Ocean) and their management. Plant Protection Quaterly. Vol 16: (2): 54-57. (2) Kranz, W. M. & T. Passini. 1997. Tecoma Stans biology and control. Informe da Pesquisa - Instituto Agronomico do Parana. No 121. (3) http://www.hear.org/pier3/testa.htm 4)http://www.landscapers.co.za/invaders.htm 5)http://www.fncw.nsw.gov.au/advisory.html

3.05

Tecoma radicans is a "rampant weed" in the Eastern USA

http://www.oardc.ohio-state.edu/scripts/weed.dll/getone.780.htm

4.01

The plant does not produce any spines, thorns or burrs.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

4.02

No evidence of it being allelopathic.

4.03

No evidence that the species is parasitic.

4.04

(1)Palatability to browse animals: low, palatability to graze animals low. (2)According to the database the fruits are not attractive to animals.

(1)http://plants.usda.gov/cgi_bin/topics.cgi (2)Southern Trees Cdrom.

4.05

Did not find any evidence that the species is toxic to animals.

4.06

Pests: Yellow-Elder is relatively pest-free with chewing insects and scale being only minor problems.

Horticopia, Trees, Shrubs and Ground covers CDROM.

4.07

(1) Although listed on the poisonous plant database I did not find any evidence that supports the species being poisonous or causing allergies in humans. It is neither listed on other web databases referred to. (2) root has medicinal properties and is considered to be a powerful diuretic, vermifuge and tonic.

(1) http://vm.cfsan.fda.gov/~djw/plantnam.html (2) Bose, T. K., Das, P and Maiti G. G. 1998. Trees of the world. Regional plant resource center. Bhubaneshwar, India.

4.08

Not fire resistant. Medium fire tolerance. No information in natural ecosystems

http://plants.usda.gov/cgi_bin/topics.cgi

4.09

(1) Plant requires full sun. (2)Grows in full sun.

(1) Southern Trees Cdrom (2)Vines, R. 1984. Trees of Central Texas. University of Texas press. Austin.

4.1

Soil texture tolerance include clay, sand and loam. Tolerates alkaline and acidic soils.

Southern Trees Cdrom.

4.11

The species is a tree not vine - did not find any evidence to it having a smothering growth habit.

4.12

Apparently :"Can grow in dense stands, inhibiting regeneration of other species." but not details given about where this is taking place or to what extent. Not reported as thickets in other locations where introduced, including Florida.

http://www.hear.org/pier3/testa.htm

5.01

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii. University of Hawaii at Press. Honolulu.

It is a shrub or small tree.

5.02

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii. University of Hawaii at Press. Honolulu.

It is a shrub or small tree.

5.03

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii. University of Hawaii at Press. Honolulu.

It is a shrub or small tree.

5.04

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii. University of Hawaii at Press. Honolulu.

It is a shrub or small tree.

6.01

No evidence/reference on reproductive failure in native habitat.

6.02

No evidence regarding sterility or non production of seeds.

6.03

No information - don’t know. According to the website Tecoma hybrid is a product of the hybridization between Tecoma stans var. stans and Tecoma stans var. angusta.

http://plantsdatabase.com/go/2048.html

6.04

'The large colorful flowers are protandrous and therefore, cross pollinated.'

Singh, J and Chauhan, S. V. S. 1999. Presence of glandular and non- glandular trichomes on anthers of Tecoma stans. Phytomorphology. Vol 49(4): 469-472

6.05

'Bees constitute the main flower visitors of the species studied… .' 2) Hummingbird pollinated

Galetto, L. 1995. Nectary structure and nectar characteristics in some Bignoniaceae. Plant systematics and evolution. Vol 196 no 1-2: 99 2)http://www.plantadviser.com/plants/tecostan.shtml

6.06

Probably not - did not find any evidence that the species can propagate itself vegetatively - no information regarding this on the CD-ROM databases either.

6.07

R. Criley, UH Department of Horticulture, personal communication

7.01

The propagates do not have any means of being attached and hence are less likely to be dispersed unintentionally.

Vines, R. 1984. Trees of Central Texas. University of Texas press. Austin.

7.02

(1) It is described as a very showy ornamental tree. (2) 'An ornamental tropical American shrub … .' These references suggest that the showiness of this species might be a good reason for it being intentionally introduced.

(1) Southern trees Cdrom. (2) Neal, M. C. 1965. In Gardens of Hawaii. Bishop museum press. Honolulu.

7.03

The seeds are 7-8 X 4 mm without wing and 20 X 6 mm with wing. It is unlikely that seeds of this size will be transported as produce contaminant.

www.hear.org/pier/testa.htm

7.04

(1) Its dispersion occurs mainly by wind but also through rain. (2)The seeds are long, flat and winged.

(1) Kranz, W. M. & T. Passini. 1997. Tecoma Stans biology and control. Informe da Pesquisa - Instituto Agronomico do Parana. No 121. (2) Vines, R. 1984. Trees of Central Texas. University of Texas press. Austin.

7.05

(1) Its dispersion occurs mainly by wind but also through rain.

7.06

7.07

No direct evidence but probably not since the propagates do not have any means of attachment.

7.08

Probably not since the seeds are wind dispersed.

8.01

Capsules are 10-20cm long and 7-8mm wide. Seeds are 7-8 X 4mm without wing and 20 X 6 mm with wing.

www.hear.org/pier/testa.htm

8.02

Probably not. high germination percentage and speed without scarification but a high mortality WITH scarification

Speroni and DeViana 2000. Requerimientos de escarificacion en semillas de especies autoctonas e invasoras.Ecologia-Austral 10 (2): 123-131

8.03

'Tebuthiuron was effective at all doses resulting in total plant mortality in 5 months.'

Passini, K & W. M. Kranz. 1997. Herbicide efficacy for trumpet flower (Tecoma stans) control in pastures.Planta Daninha. Vol 15 (2): 190-197.

8.04

Coppice potential: Yes, Resprout ability: Yes. Response to regular mutilation unknown

http://plants.usda.gov/cgi_bin/topics.cgi

8.05

No information


Need more info? Have questions? Comments? Information to contribute? Contact PIER!


[ Return to PIER homepage ] [Risk assessment page]


This page updated 7 March 2005