Pacific Island Ecosystems at Risk (PIER)


Thrinax parviflora


RISK ASSESSMENT RESULTS: Low risk, score: -6


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

Thrinax parviflora (Thatch palm, broom 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

n

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

n

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

n

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

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

n

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

n

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

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

4

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

y

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

n

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:

-6

Supporting data:

Source

Notes

1.01

No evidence

1.02

No evidence of naturalization.

1.03

No evidence

2.01

(1) Native to Jamaica. 'This robust palm will thrive in tropical as well as subtropical climates and tolerates an occasional light frost. ' (2) Range: Florida Keys, Bahamas, Cuba, Jamaica, Haiti

(1)http://www.rarepalmseeds.com/pix/ThrPar.shtml (2)http://www.interaktv.com/BOTANY/PalmTtoZ.html#Thrinax

2.02

2.03

In Jamaica, grows on Well drained limestone up to 3000 feet but the plants at higher elevation have a different morphology. Cultivated plants are the lower elevation mophology.

Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona

2.04

(1) Native to Jamaica. 'This robust palm will thrive in tropical as well as subtropical climates and tolerates an occasional light frost. ' (2) Range: Florida Keys, Bahamas, Cuba, Jamaica, Haiti

(1)http://www.rarepalmseeds.com/pix/ThrPar.shtml (2)http://www.interaktv.com/BOTANY/PalmTtoZ.html#Thrinax

2.05

(1)grown in Florida (native) (2)Introduced to California (3)Germany (4)Hawai‘I (5)Australia (6)Texas

(1)http://www.palmseeds.org/download/palmsandgardens_price_list.pdf (2)http://www.junglemusic.net/Palm%20images%20T%20through%20Z.htm (3)http://www.roepke-versand.de/index.html (4)http://www.orphic.com/palmcat/palms11.html (5)http://www.palmsforbrisbane.com.au/pricen-w.html (6)http://www.raingardens.com/psst/articles/artic06.htm

3.01

No evidence of introductions or naturalization.

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

No evidence

Strong, A.M. & Johnson, M.D. 2001. Exploitation of a seasonal resource by non breeding plain and white crowned pigeons: Implications for conservation of tropical dry forests. Wilson Bulletin113(1): 73-77.

4.02

No evidence

4.03

No evidence

4.04

No information

4.05

No evidence

4.06

No information regarding pests associated with T. parviflora.

4.07

No evidence

4.08

Lush, evergreen foliage

4.09

Light requirement: High

http://edis.ifas.ufl.edu/EH157

4.1

(1)It does well on poor, rocky, or sandy soils, as long as it is well drained (2) sand dunes (3)Well drained limestone

(1)http://www.rarepalmseeds.com/pix/ThrPar.shtml (2)Ayora, N. N.; Orellana, R.1993. Physicochemical soil factors influencing the distribution of two coastal palms in Yucatan, Mexico. Principes 37:82-91. (3)Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona

4.11

A tree

Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona

4.12

No evidence

5.01

A palm in Arecaceae.

(1)http://www.rarepalmseeds.com/pix/ThrPar.shtml (2)http://www.interaktv.com/BOTANY/PalmTtoZ.html#Thrinax

5.02

5.03

5.04

6.01

In this study the abundance of white crowned pigeons in Jamaica was correlated to the fruit production of T. parviflora.

Strong, A.M. & Johnson, M.D. 2001. Exploitation of a seasonal resource by non breeding plain and white crowned pigeons: Implications for conservation of tropical dry forests. Wilson Bulletin113(1): 73-77.

6.02

Fast germinating from seed

http://www.banana-tree.com/catalog.cfm?category=8

6.03

No evidence

6.04

No evidence

6.05

(1)flowers ivory to yellowish [typical insect pollinated palm flowers] (2)Attracts honeybees

(1)Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona (2)http://www.netcall.com.mx/abejas/en/plants/plants/Bee.G.htm

6.06

a tree

Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona

6.07

(1)Growth rate: Slow [minimum for a slow growing palm] (2)T. radiata attains a height of 3 m at age 31-55 yr. Both species start reproducing when 4 m tall

(1)http://edis.ifas.ufl.edu/EH157 (2)Olmsted, I.; Alvarez-Buylla, E. R. 1995. Sustainable harvesting of tropical trees: demography and matrix models of two palm species in Mexico. Ecological Applications 5:484-500

7.01

Probably not - the propagules do not have any means of attachment.

Strong, A.M. & Johnson, M.D. 2001. Exploitation of a seasonal resource by non breeding plain and white crowned pigeons: Implications for conservation of tropical dry forests. Wilson Bulletin113(1): 73-77.

7.02

ornamental palm

7.03

large seeds

7.04

bird-dispersed

7.05

bird-dispersed

7.06

(1)This study in Jamaica discusses the fruits being eaten by pigeons (2)Fruit a drupe, white or ivory colored

Strong, A.M. & Johnson, M.D. 2001. Exploitation of a seasonal resource by non breeding plain and white crowned pigeons: Implications for conservation of tropical dry forests. Wilson Bulletin113:: 73-77. (2)Adams, G.D. Flowering plants of Jamaica. University of the West Indies. Mona

7.07

no means of attachment

7.08

bird-dispersed

8.01

No information regarding seed size and number.

8.02

Most all palms have short-lived seeds

8.03

No evidence that the species is being controlled for.

8.04

No information

8.05

Don’t know.


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This page updated 4 November 2005