Pacific Island Ecosystems at Risk (PIER)


Pandanus pygmaeus


RISK ASSESSMENT RESULTS: Low risk, score: 0


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment
  Pandanus pygmaeus (small screwpine) Score Answer
1.01 Is the species highly domesticated? n 0
1.02 Has the species become naturalized where grown? n  
1.03 Does the species have weedy races? 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” 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) n 0
2.04 Native or naturalized in regions with tropical or subtropical climates y 1
2.05 Does the species have a history of repeated introductions outside its natural range?  y=-2 n  
3.01 Naturalized beyond native range         y = 1*multiplier (see Append 2), n= question 2.05 n 0
3.02 Garden/amenity/disturbance weed                              y = 1*multiplier (see Append 2) n 0
3.03 Agricultural/forestry/horticultural weed                         y = 2*multiplier (see Append 2) n 0
3.04 Environmental weed                                                     y = 2*multiplier (see Append 2) n 0
3.05 Congeneric weed                                                          y = 1*multiplier (see Append 2) n 0
4.01 Produces spines, thorns or burrs y 1
4.02 Allelopathic n 0
4.03 Parasitic n 0
4.04 Unpalatable to grazing animals    
4.05 Toxic to animals n 0
4.06 Host for recognized pests and pathogens    
4.07 Causes allergies or is otherwise toxic to humans y 1
4.08 Creates a fire hazard in natural ecosystems n 0
4.09 Is a shade tolerant plant at some stage of its life cycle    
4.1 Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)    
4.11 Climbing or smothering growth habit n 0
4.12 Forms dense thickets n 0
5.01 Aquatic n 0
5.02 Grass n 0
5.03 Nitrogen fixing woody plant n 0
5.04 Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) n 0
6.01 Evidence of substantial reproductive failure in native habitat n 0
6.02 Produces viable seed. y 1
6.03 Hybridizes naturally    
6.04 Self-compatible or apomictic n -1
6.05 Requires specialist pollinators    
6.06 Reproduction by vegetative fragmentation y 1
6.07 Minimum generative time (years)                 1 year = 1, 2 or 3 years = 0, 4+ years = -1   0
7.01 Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) n -1
7.02 Propagules dispersed intentionally by people y 1
7.03 Propagules likely to disperse as a produce contaminant n -1
7.04 Propagules adapted to wind dispersal n -1
7.05 Propagules water dispersed y 1
7.06 Propagules bird dispersed n -1
7.07 Propagules dispersed by other animals (externally) n -1
7.08 Propagules survive passage through the gut n -1
8.01 Prolific seed production (>1000/m2)    
8.02 Evidence that a persistent propagule bank is formed (>1 yr)    
8.03 Well controlled by herbicides    
8.04 Tolerates, or benefits from, mutilation, cultivation, or fire    
8.05 Effective natural enemies present locally (e.g. introduced biocontrol agents)    
  Total score:   0

Supporting data:

  Notes Reference
1.01 No evidence  
1.02 No evidence  
1.03 No evidence  
2.01 (1)The herbarium specimens of P. Pgymaeus were all collected from Madagascar. (2)Paleotropic genus of probably 600-700 species. The greatest diversity in the genus is found in Madagascar (100 species) and Malesia (450-500 species). (1)http://mobot.mobot.org/cgi-bin/search_vast  (2)Wagner, W. L., Herbst, D. R., Sohmer, S. H. 1990. Manual of flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii.
2.02    
2.03 Probably not - the altitudinal range of none of the specimens collected from Madagascar was greater than 800 m. http://mobot.mobot.org/cgi-bin/search_vast
2.04 Paleotropic genus of probably 600-700 species. The greatest diversity in the genus is found in Madagascar (100 species) and Malesia (450-500 species). Wagner, W. L., Herbst, D. R., Sohmer, S. H. 1990. Manual of flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii.
2.05 No evidence  
3.01 No evidence  
3.02 No evidence  
3.03 No evidence  
3.04 No evidence  
3.05 No evidence  
4.01 (1)Leaves green and spiny.  (2)Thorny and hard green fruit. (3)Toothed leaf with spines at top (1)http://mobot.mobot.org/cgi-bin/search_vast?ssdp=00922061  (2)http://mobot.mobot.org/cgi-bin/search_vast?ssdp=01202228  (3)http://mobot.mobot.org/cgi-bin/search_vast?ssdp=01225053
4.02 No evidence  
4.03 No evidence  
4.04 Don’t know  
4.05 No evidence  
4.06 No evidence  
4.07 Edible fruits. http://mobot.mobot.org/cgi-bin/search_vast?ssdp=00745887
4.08 Probably not - an evergreen, low growing coastal species- grown in beaches, not know to form thickets.  
4.09 Requires full sun to partial shade. [No other evidence regarding ligh requirement. Unable to judge base on one reference]. http://www.nparks.gov.sg/nursery/
spe_by_search_details.asp?specode=6614&searchdetail=detail#
4.1 Suitable for seaside planting. [Suggests it can tolerate sandy soils and salt. No other evidence regarding soil requirement. Unable to judge base on one reference]. http://www.nparks.gov.sg/nursery/
spe_by_search_details.asp?specode=6614&searchdetail=detail#
4.11 No evidence  
4.12 No evidence  
5.01 Terrestrial (genus characteristic) Wagner, W. L., Herbst, D. R., Sohmer, S. H. 1990. Manual of flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii.
5.02 (1)A shrub.  (2)Treelet growing to 4 m high, with stilt roots. Lowest branches touching soil and rooting. Fruit unripe, green. (1)http://www.nparks.gov.sg/nursery/
spe_by_search_details.asp?specode=6614&searchdetail=detail#  (2)http://mobot.mobot.org/cgi-bin/search_vast?ssdp=01385163
5.03 No evidence  
5.04 Treelet growing to 4 m high, with stilt roots. Lowest branches touching soil and rooting. Fruit unripe, green. http://mobot.mobot.org/cgi-bin/search_vast?ssdp=01385163
6.01 Speciment notes from collections in Madagascar indicate the plants to be flowering and fruiting. http://mobot.mobot.org/cgi-bin/search_vast
6.02 Probably yes - seeds sold commercially online. http://www.equatorialexotics.com/price.htm
6.03 Don’t know  
6.04  (1)Pandanaceae are an ancient family of dioecious monocots dating from the early to mid-Cretaceous, and comprising three extant genera Sararanga, Freycinetia and Pandanus.  (2)Genus characteristic - 'They are dioecious, with male and female flowers produced on different plants. The flowers of the male tree are 2-3 cm long and fragrant, surrounded by narrow, white bracts. The female tree produces flowers with round fruits that are also bract-surrounded.' (1)Callmander, Martin W.; Chassot, Philippe; Kupfer, Philippe, et al. Recognition of Martellidendron, a new genus of Pandanaceae, and its biogeographic implications. Taxon 52 (4) : 747-762 November 2003
(2)http://en.wikipedia.org/wiki/Pandanus
6.05 Don’t know - plant is dioeceous  
6.06  'Treelet growing to 4 m high, with stilt roots. Lowest branches touching soil and rooting. Fruit unripe, green.' http://mobot.mobot.org/cgi-bin/search_vast?ssdp=01385163
6.07    
7.01 No evidence that the species is grown in heavilty trafficked areas.  
7.02 (1)Grown for it ornamental foliage.   (2)Plant available for purchase via internet. (1)http://www.nparks.gov.sg/nursery/
spe_by_search_details.asp?specode=6614&searchdetail=detail#  (2)http://translate.google.com/translate?hl=en&sl=it&u=http://
www.topshare.de/c211.html&prev=/search%3Fq%3D
Pandanus%2Bpygmaeus%26hl%3Den%26lr%3D%26sa%3DG
7.03 Probably not - no evidence that the species grows in or around seed crops.  
7.04 Probably not - not known in the genus.  
7.05 Probably yes - (1)Grows on beaches. [Congener P. tectorius is distributed from island to island by sea drifted fruits].  (2)Speciment (Missouri Botanical Garden specimen id {00922061}, specimen id {00955847}
)  was collected growing on the banks of the river Iantara in Madagascar.
(1)Ref for P. tectoreius - Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii. Page -1480  (2)http://mobot.mobot.org/cgi-bin/search_vast?ssdp=00922061
7.06    
7.07 Based on the genus characteristics - no evidence that the propagules have any means of attachment.  Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii. Page -1480
7.08 Probably not - in the congener P. tectorius crabs are known to disperse the seeds by carrying them and discarding the woody part that contains the seeds.  
8.01 Genus characteristic - The fruits are globose, 10 to 20 cm in diameter, and have many prism-like sections, resembling the fruit of the pineapple. [In P. tectorius the seeds are 8 - 15 mm long -  Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press. Honolulu. Hawaii. Page -1480]. http://en.wikipedia.org/wiki/Pandanus
8.02 No evidence regarding seed longevity.  
8.03 No evidence that the species is being controlled for.  
8.04 don’t know.  
8.05 Don’t know.  

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This page created 23 December 2006