Pacific Island Ecosystems at Risk (PIER)


Ravenala madagascariensis


RISK ASSESSMENT RESULTS: Evaluate, score: 5


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

Ravenala madagascariensis (Traveller's tree or palm)

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

n

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

n

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

y

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

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

n

6.04

Self-compatible or apomictic

y=1, n=-1

y

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

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

n

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

y

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

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:

5

Supporting data:

Source

Notes

1.01

No evidence.

1.02

It is problem species in Mauritius.

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

1.03

No evidence.

2.01

Climatic zones in region or origin: tropical, arid, subtropical and moist. Invaded zones are subtropica moist.

Cronk, Q. C. B. and Fuller J. L. 1995. Plant Invaders. Chapman and Hall. London.

2.02

Climatic zones in region or origin: tropical, arid, subtropical and moist. Invaded zones are subtropica moist.

Cronk, Q. C. B. and Fuller J. L. 1995. Plant Invaders. Chapman and Hall. London.

2.03

1)Hardiness range 10A to 11. 2)Requires consistently moist soil

1)Horticopia: Trees, Shrubs and Groundcover. Cd-ROM Database. 2)http://plantsdatabase.com/go/2068.html

2.04

(1)Native to Madagascar. (2) 'Malagasy is the original habitat of this plant but it is now planted in many tropical countries for the spectacular and curious appearance.'

(1)http://www.hear.org/pier3/ramad.htm (2)Bose, T.K., Das, P. and Maiti, G.G. 1998. Trees of the World. Volume 1. Regional Plant Resource Centre. Orissa. India.

2.05

'Malagasy is the original habitat of this plant but it is now planted in many tropical countries for the spectacular and curious appearance.'

Bose, T.K., Das, P. and Maiti, G.G. 1998. Trees of the World. Volume 1. Regional Plant Resource Centre. Orissa. India.

3.01

It is problem species in Mauritius.

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

3.02

No evidence.

3.03

No evidence.

3.04

'Ravenala madagascariensis is a big problem in Mauritius, especially on mid-altitude (3-600 m) south and west facing slopes in and around the Black River Gorges National Park. In large areas it almost forms monocultures, with little or no native vegetation left.'

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

3.05

Monotypic species in the genus.

4.01

No evidence.

Bose, T.K., Das, P. and Maiti, G.G. 1998. Trees of the World. Volume 1. Regional Plant Resource Centre. Orissa. India.

4.02

No evidence.

4.03

No evidence.

4.04

No information.

4.05

No evidence.

4.06

(1)This site lists 15 species of fungi to be associated with R. madagascariensis. (2)The fungus causing leaf spot disease of arecanut was isolated and identified as Colletotrichum gloeosporioides [Glomerella cingulata ]. African oil palm (Elaeis guineensis ), Fish tail palm (Caryota urens ), travellers palm (Ravenala madagascariensis ) and yellow palm (Areca lutescens ) were artificial hosts of the pathogen following inoculation of the test fungus. (3)Curvularia lunata possibly a recognized pest. (4) Deightoniella torulosa causes diseases in banana and plantain.

(1)http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm (2) Padalkar, N. R.; Mandokhot, A. M.; Fugro, P. A. 1996. Leaf spot disease of arecanut in Konkan region of Maharashtra. Indian Cocoa, Arecanut and Spices Journa. Vol.20, No.4, pp.111-112. (3)http://www.ars.usda.gov/is/np/pearlmillet/tab4.htm (4)http://www.scisoc.org/resource/common/names/banana.htm

4.07

No evidence.

4.08

Leafy plant of wet habitats.

4.09

(1)Partial shade to full sun. 'Traveller's tree will grow best in full sun, though potted plants may be grown in shade for a period of time.' (2)Full sun. (3)Full sun

(1)Horticopia: Trees, Shrubs and Groundcover. Cd-ROM Database. (2)Plant Master 5.5 Cd-ROM database. (3)http://plantsdatabase.com/go/2068.html

4.1

Clay, Sandy, Loam, slightly alkaline, neutral and acidic.

Horticopia: Trees, Shrubs and Groundcover. Cd-ROM Database.

4.11

No evidence. It is not a vine.

Horticopia: Trees, Shrubs and Groundcover. Cd-ROM Database.

4.12

Apparently forms "dense stands" in certain areas in Mauritius (but the unusual growth form is not conductive to thicket formation).

Cronk, Q. C. B. and Fuller J. L. 1995. Plant Invaders. Chapman and Hall. London.

5.01

It is a palm like tree belonging to Musaceace.

Horticopia: Trees, Shrubs and Groundcover. Cd-ROM Database.

5.02

5.03

5.04

6.01

No evidence.

6.02

Propagate from seed in spring or by division of suckers at any time.

http://florawww.eeb.uconn.edu/acc_num/198700180.html

6.03

Monotypic species in the genus.

http://www.floridata.com/ref/R/rave_mad.cfm

6.04

'Apart from reproducing vegetatively the ability of Ravenala to set seed when grown outside its normal range in the absence of coevolved pollinator(s) either by selfing or by using a suitable indigenouspollinators could allow the speceis to assume pest status in parts of the tropics where it is planted as an ornamental.' 'However the species is not locked into cross pollination and may self fertilize although the quality /quantity of seed may be decreased below that achieved by outbreeding.'

Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

6.05

(1)Pollinated by lemurs. (2)Our observations in the field also show that Varecia variegata: consistently and almost exclusively visit the flowers of Ravenala; carry pollen on their fur between flowers on the same plant and between conspecific plants; do not destroy the flowers while obtaining the nectar; and appear to be highly dependent on nectar as a food source during specific times of the year. 3)Pollinated by birds 

(1)http://florawww.eeb.uconn.edu/acc_num/198700180.html (2) Kress, WJ; Schatz, GE; Andrianifahanana, M; Morland, HS. 1994. Pollination of Ravenala madagascariensis (Strelitziaceae) by lemurs in Madagascar: Evidence for an archaic coevolutionary system? American journal of botany. v. 81 (5) p. 542-551 3)Little et al. 1974. Trees of Puerto Rico and the Virgin Islands. Volume 2. US Department of Agriculture

6.06

(1)Reproduces vegetatively by suckering. (2)Propagate from seed in spring or by division of suckers at any time.

(1)Cronk, Q. C. B. and Fuller J. L. 1995. Plant Invaders. Chapman and Hall. London. (2)http://florawww.eeb.uconn.edu/acc_num/198700180.html

6.07

No information.

7.01

(1)Seed are relatively large with 9 to 14 mm in size. Also propagules do not have any means of attachment.

(1)Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

7.02

(1)Flower showy, fruit not showy and not edible but (2)seeds are edible. For the above 2 reasons it is very likely that the species may be intentionally introduced.

(1)Southern Trees. CD-ROM database. (2)http://www.neoflora.com/cgi-bin/plant_profile.cgi?plant_sid=14158

7.03

(1)Seeds have conspicuous blue arils (2)Seed are relatively large about 9 to 14 mm.

(1)http://www.hear.org/pier3/ramad.htm (2)Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

7.04

7.05

7.06

(1)Seed dispersal by birds (fleshy aril). (2) 'In Darwin, the blue aril coated seeds are occasionally consumed by Oriolus sagitattus (Oriolidae). Generally the seeds remain in position until the browned inflorescence decays, allowing the seeds to fall to the ground.' Although dispersal in this species is not clear and the authors call for further research regarding dispersal.

(1)Cronk, Q. C. B. and Fuller J. L. 1995. Plant Invaders. Chapman and Hall. London. (2)Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

7.07

Propagules have no means of attachment.

7.08

Dispersal in this species is not well understood. It is not sure whether the seeds are digested or not.

Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

8.01

(1)Fruit is 3 valves capsule with numerous seeds. (2)The hard brown seeds are 9 to 14 mm.

(1)Bose, T.K., Das, P. and Maiti, G.G. 1998. Trees of the World. Volume 1. Regional Plant Resource Centre. Orissa. India. (2)Calley, M Braithwate, R.W. and Ladd, P. G. 1993. Reproductive biology of Ravenala madagascariensis as an alien species. Biotropica Vol 25(5): 61-72.

8.02

No information.

8.03

No evidence that this species is being controlled for.

8.04

No information.

8.05

Don’t know.


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This page updated 8 March 2005