Pacific Island Ecosystems at Risk (PIER)


Saraca indica


RISK ASSESSMENT RESULTS: Low risk, score: -7


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

Saraca indica (Ashoka tree)

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

1

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

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

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

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

y

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

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

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

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

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

n

8.05

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

y=-1, n=1

Total score:

-7

Supporting data:

Source

Notes

1.01

No evidence

1.02

No evidence of naturalization.

1.03

No evidence

2.01

Native to SE Asia and grows wildly in evergreen forests as an understory.

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

2.02

adapted to humid lowland tropics [maybe too tropical]

2.03

(1)Saraca Indica is grown all over India. It occur upto the altitudes 600 meters. (2)It commonly grows wild along streams or in the shade of evergreen forests in India, Burma, Ceylon and inthe Malayan region. (3)On humid lowlands and coastal plains Saraca indica is favoured

(1)http://ayurveda-foryou.com/archive/ashok.html (2)http://www.sriaurobindosociety.org.in/flrarch/flroct01.htm (3)http://www.fao.org/docrep/X5325e/x5325e08.htm

2.04

Native to SE Asia and grows wildly in evergreen forests as an understory.

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

2.05

[a rare tree in introduced range] (1)Grown in Tahiti (2)introduced to Florida (3)Singapore (4)Tanzania -- trials only?

(1)http://www.tahiti-postoffice.com/english/stamps/history.html (2)http://www.tfts.org/auction_2001.htm (3)http://www.iftco.com.sg/ (4)http://www.fao.org/docrep/X5325e/x5325e08.htm

3.01

No evidence of naturalization.

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

No evidence

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

4.02

[lab results are likely irrelevant to field situation] Aqueous leaches of Saraca indica inhibited the seed germination and seedling growth of congress grass (Parthenium hysterophorous) by 62.5 and 36.83% respectively.

Dhawan, S.R. and Gupta, S.A. 1996. Advances in plant sciences. 9(2): 151-154

4.03

No evidence

4.04

Probably palatable (a legume)

4.05

No evidence

4.06

This website lists 7 fungi to be associated with S. indica. None found to be recognized pests.

http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm

4.07

No evidence

4.08

evergreen tree

4.09

(1) '…grows well in well drained soils under shade.' (2)grows in the shade of evergreen forests

(1)Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244. (2)http://www.sriaurobindosociety.org.in/flrarch/flroct01.htm

4.1

No information regarding suitable soil.

4.11

No evidence - not a vine.

4.12

No evidence

5.01

5.02

5.03

It is leguminous N-fixing tree.

http://www.winrock.org/forestry/factpub/nftlist.htm

5.04

6.01

Propagates through seed.

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

6.02

Propagates through seed.

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

6.03

No information

6.04

No information

6.05

[based on open floral morphology] Flowers are fragrant. They are 7.5-10 cms across. Calyx is yellow to orange and finally red. Its stamens are 7 to 8. The filaments are filiform.[Stigmas and stamens protrude several centimeters beyond flowers -- small insects would be ineffective. Strong smelling at night suggests nocturnal pollinator]

http://www.pioneerherbs.com/saraca_indica.htm

6.06

Propagates through seed.

Naginhal, S.G. 1986. Some beautiful trees of Bangalore. Myforest. 22(4) 241-244.

6.07

Growth rate: medium

http://www.afforestationmanual.com/pdffiles/Extract_2.pdf

7.01

large seeds, no means of attachment

http://www.sriaurobindosociety.org.in/flrarch/flroct01.htm

7.02

Probably yes - 'It is cultivated in many gardens because of its decorative orange red flowers and evergreen beautiful foliage. '

http://ayurveda-foryou.com/archive/ashok.html

7.03

no produce

7.04

large seeds, no wind adaptation

http://www.sriaurobindosociety.org.in/flrarch/flroct01.htm

7.05

Probably not as the species does not grow along the coast, nor along rivers.

7.06

no evidence

7.07

no evidence

7.08

no evidence of consumption

8.01

4 to 8 brown seeds in a pink or rosy 6-10 inches long seed pod which turns later into green and finally brown.

http://www.sriaurobindosociety.org.in/flrarch/flroct01.htm

8.02

Low seed viability

http://www.afforestationmanual.com/pdffiles/Extract_2.pdf

8.03

No evidence that the species is being controlled for.

8.04

Coppice ability: weak

http://www.afforestationmanual.com/pdffiles/Extract_2.pdf

8.05

Don’t know.


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


[ Return to PIER homepage ] [Risk assessment page]


This page updated 3 November 2005