Pacific Island Ecosystems at Risk (PIER)
RISK ASSESSMENT RESULTS: High risk, score: 7
|
Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Information on Risk Assessments Original risk assessment |
| Bauhinia purpurea (purple bauhinia, orchid tree, butterfly tree) | Answer | Score | |
| 1.01 | Is the species highly domesticated? | n | 0 |
| 1.02 | Has the species become naturalized where grown? | y | |
| 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) | y | 1 |
| 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 | y | |
| 3.01 | Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05 | y | 2 |
| 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) | y | 4 |
| 3.05 | Congeneric weed y = 1*multiplier (see Append 2) | y | 2 |
| 4.01 | Produces spines, thorns or burrs | n | 0 |
| 4.02 | Allelopathic | ||
| 4.03 | Parasitic | n | 0 |
| 4.04 | Unpalatable to grazing animals | n | -1 |
| 4.05 | Toxic to animals | n | 0 |
| 4.06 | Host for recognized pests and pathogens | n | 0 |
| 4.07 | Causes allergies or is otherwise toxic to humans | n | 0 |
| 4.08 | Creates a fire hazard in natural ecosystems | ||
| 4.09 | Is a shade tolerant plant at some stage of its life cycle | y | 1 |
| 4.1 | Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) | y | 1 |
| 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 | y | 1 |
| 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 | y | 1 |
| 6.05 | Requires specialist pollinators | n | 0 |
| 6.06 | Reproduction by vegetative fragmentation | n | -1 |
| 6.07 | Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 | 3 | 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 | n | -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 | ||
| 8.01 | Prolific seed production (>1000/m2) | n | -1 |
| 8.02 | Evidence that a persistent propagule bank is formed (>1 yr) | n | -1 |
| 8.03 | Well controlled by herbicides | ||
| 8.04 | Tolerates, or benefits from, mutilation, cultivation, or fire | y | 1 |
| 8.05 | Effective natural enemies present locally (e.g. introduced biocontrol agents) | ||
| Total score: | 7 |
Supporting data:
|
Notes |
Reference |
|
|
1.01 |
No evidence |
|
|
1.02 |
"Purple Bauhinia is a deciduous to semi-evergreen multi-trunk small tree with a rounded canopyand coarse textured foliage; although this is a Southeast Asian native, it is extensively naturalizedin subtropical and tropical climates and has become invasive in some regions." |
http://66.102.7.104/search?q=cache:8Y3WKOcw3EAJ:aggie-horticulture.tamu.edu/syllabi/308/Lists/second%2520ed/Bauhiniagalpinii.pdf |
|
1.03 |
No evidence |
|
|
2.01 |
(1)B. purpurea is widely distributed throughout the Indo-Pakistan subcontinent, and has been introduced into other tropical and subtropical regions, including Africa, South-East Asia and Australia. (2)This tree is native of South-East Asia and often cultivated in India |
(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://ces.iisc.ernet.in/fish/flora.html |
|
2.02 |
B. purpurea is widely distributed throughout the Indo-Pakistan subcontinent, and has been introduced into other tropical and subtropical regions, including Africa, South-East Asia and Australia. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
2.03 |
(1)Altitude range: 500 - 1500 m - Mean annual rainfall: 1000 - 5000 mm - Rainfall regime: summer; winter; bimodal - Dry season duration: 4 - 6 months - Mean annual temperature: 12 - 21ºC - Mean maximum temperature of hottest month: 30 - 43ºC - Mean minimum temperature of coldest month: 7 - 11ºC - Absolute minimum temperature: -1 - 10ºC (2) Hardiness zone 9B to 11 (3)Hardiness zones 9A- 11 |
(1)CAB International, 2000. Forestry Compendium Global
Module. Wallingford, UK: CAB International. (2)http://hort.ufl.edu/trees/BAUPURA.pdf#search=%22%22bauhinia |
|
2.04 |
B. purpurea is widely distributed throughout the Indo-Pakistan subcontinent, and has been introduced into other tropical and subtropical regions, including Africa, South-East Asia and Australia. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
2.05 |
B. purpurea is widely distributed throughout the Indo-Pakistan subcontinent, and has been introduced into other tropical and subtropical regions, including Africa, South-East Asia and Australia. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
3.01 |
"Purple Bauhinia is a deciduous to semi-evergreen multi-trunk small tree with a rounded canopyand coarse textured foliage; although this is a Southeast Asian native, it is extensively naturalizedin subtropical and tropical climates and has become invasive in some regions." |
http://66.102.7.104/search?q=cache:8Y3WKOcw3EAJ:aggie-horticulture.tamu.edu/syllabi/308/Lists/second%2520ed/Bauhiniagalpinii.pd |
|
3.02 |
No evidence |
|
|
3.03 |
No evidence |
|
|
3.04 |
(1)In Florida Dade County - listed as a plant that "may not be planted within 500 feet of native plant communities which they have been known to invade." (2)Bauhinia purpurea is also known as Fall Orchid Tree, Purple Orchid Tree, or Pata De Vaca; Purple Bauhinia is a deciduous to semi-evergreen multi-trunk small tree with a rounded canopy and coarse textured foliage; although this is a Southeast Asian native, it is extensively naturalized in subtropical and tropical climates and has become invasive in some regions. |
(1)http://miami-dade.ifas.ufl.edu/Programs/urbanhort/publications/PDF/Miami-Dade-County-Invasive-Plants.pdf#search=%22%22bauhinia%20purpurea%22%20 |
|
3.05 |
Bauhinia variegata - (1)Category 1 invasive species. This category identifies "invasive exotics that are altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives"Noted as a common escape, abundantly invading disturbed areas in particular. Naturalized in the Caribbean and elsewhere in the Neotropics as well. Spreading from sites where previously planted in Big Cypress National Preserve. Found in 10 conservation areas in Dade County; displacing native vegetation in hammock margins and occasionally in globally imperiled pine rocklands. Reported now from natural areas in four counties: Pinellas, Lee, Dade, and Palm Beach, including the Loxahatchee National Wildlife Refuge and Everglades National Park. (2)Category 3 invader in South Africa [lowest rating] (3)Caution: This species has been identified as a potential weed in the Maranoa (Ma) district [Australia] |
(1)http://216.239.53.100/search?q=cache:-a8bchEIHREC:www.fleppc.org |
|
4.01 |
No evidence of such structures. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
4.02 |
'The species that exhibited allelopathy or allelopathic-like patterns included Acacia confusa, Bauhinia purpurea, Eucalyptus robusta, Glochidion fortueni, Phyllostachys spp., Rhododendron spp. Sinobamboosa kunishii, Sinocalamus oldhami and Yushania nittakavamensis. In addition, Miscanthus floridulus, a widely predominant grass, showed strong allelopathic potential. Other grasses Acroceras macrum, Cynodon dactylon, Chloris gayana, Digitaria decumbens, Eragrostis curvula and Panicum maximum also exhibited relatively pure stand in the field. Reduced yield in the second crop was attributed primarily to an autointoxication mechanism. The autointoxication of rice plants was due to the phytotoxins produced during the decomposition of rice residues in the soil. Six phytotoxic phenolics and several unknown compounds were found to be distributed in these plants, although the quantity and quality of toxins present in these plants was different. The identified toxins include ferulic, p-coumaric, syringic, vanillic, p-hydroxybenzoic, and o-hydroxyphenylacetic acids. The interaction of environmental factors with the phytotoxins is discussed.' [Dont know if allelopathic under natural conditions]. |
|
|
4.03 |
No evidence |
|
|
4.04 |
Abstract - "Abstract Shortage of fodder is a major constraint to livestock production in Nepal. The genetic variation in canopy biomass production of Bauhinia purpurea L, a very important fodder species in Nepal, was estimated in a Breeding Seed Orchard in order to examine the potential of simple, low input breeding. Substantial genetic variation could be observed suggesting that low input breeding based on simple phenotypic selection can provide biomass gain in the order of 2–5% per year. Very high correlation was observed between stem diameter (cross section area) and total biomass, making farmer based selection relevant. Jointly, these results suggest that low input domestication is a promising option for improving fodder production in Nepal and thereby help to improve rural livelihood and development. A multiple population approach is recommended. " |
http://www.springerlink.com/content/p17085x162674471/ |
|
4.05 |
No evidence |
|
|
4.06 |
The following were listed to be
associated with Bauhinia purpurea. Alternaria cassiae fungus |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
4.07 |
No evidence |
|
|
4.08 |
A deciduous tree with aromatic foliage however usually grown as a single accent tree and generally inhabits regions with 1000 - 5000 mm rainfall (wet regions). [Inconclusive evidence regarding fire]. |
http://davesgarden.com/pf/go/2325/index.html |
|
4.09 |
Sun to partial shade. |
http://davesgarden.com/pf/go/2325/index.html |
|
4.1 |
(1)Tolerates saline soils (2)Soil tolerances clay, loam, sand, slightly alkaline, acidic, well drained. |
(1)CAB International, 2000. Forestry Compendium Global
Module. Wallingford, UK: CAB International. (2)http://hort.ufl.edu/trees/BAUPURA.pdf#search=%22%22bauhinia%20purpurea |
|
4.11 |
No evidence of a climbing habit. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
4.12 |
No evidwence |
|
|
5.01 |
A fast growing tree- 30 to 35 ft in height. |
http://hort.ufl.edu/trees/BAUPURA.pdf#search=%22%22bauhinia%20purpurea%22%22 |
|
5.02 |
|
|
|
5.03 |
Ability to fix nitrogen. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
5.04 |
|
|
|
6.01 |
No evidence |
|
|
6.02 |
Propagation by seed. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
6.03 |
'Bauhinia blakeana (Leguminosae subfam. Caesalpinioideae tribe Cercideae), or the Hong Kong Orchid Tree, is of great horticultural value. It is completely sterile and is shown here to be the result of hybridization between the largely sympatric species, B. purpurea and B. variegata. Although the analysis of patterns of morphological variation revealed only a few examples of phenotypic intermediacy, study of intersimple sequence repeat (ISSR) markers enabled unequivocal identification of the parental species due to the presence of additive inheritance of alleles and the absence of any bands that are unique to B. blakeana. Investigation of aspects of the reproductive biology of the taxa furthermore revealed that the parental species are largely xenogamous, have flowering periods that overlap seasonally and temporally, and share common pollinators. Evidence is provided to show that B. blakeana is not naturally stabilized and is only maintained horticulturally by artificial propagation. It is therefore recommended that the hybrid be regarded as a horticultural cultivar rather than a naturally occurring species; a new cultivar name, Bauhinia 'Blakeana', is accordingly validated.' [Dont know - No evidence of hybridization under natural circumstances]. |
Hybrid origin of "Bauhinia blakeana" (Leguminosae: Caesalpinioideae), inferred using morphological, reproductive, and molecular data . By: Lau, C. P. Y.; American Journal of Botany 92 (3), 2005, p.525-533 (Journal article) |
|
6.04 |
'The controlled pollination experiments conducted during the present research provide clear evidence that B. blakeana is completely sterile: no seeds were set after any of the six experimental treatments (Table 3). This is in marked contrast to both B. purpurea and B. variegata, which are shown to be capable of both autogamy and xenogamy.' |
Hybrid origin of "Bauhinia blakeana" (Leguminosae: Caesalpinioideae), inferred using morphological, reproductive, and molecular data . By: Lau, C. P. Y.; American Journal of Botany 92 (3), 2005, p.525-533 (Journal article) |
|
6.05 |
'Field observations revealed that B. purpurea and B. variegata were both primarily visited by honeybees (Apis cerana and A. mellifera) and to a lesser extent by bamboo carpenter bees (Xylocopa iridipennis) and the common mormon butterfly (Papilio polytes). Pollen was observed adhering to the bodies of these insects, indicating that they were likely to be effective pollinators. The nectar produced by all three species was sucrose dominated (66, 63, and 80% sucrose, respectively, for B. purpurea, B. blakeana, and B. variegata); this is typical of flowers visited by long-tongued bees, wasps and lepidopterans.' |
Hybrid origin of "Bauhinia blakeana" (Leguminosae: Caesalpinioideae), inferred using morphological, reproductive, and molecular data . By: Lau, C. P. Y.; American Journal of Botany 92 (3), 2005, p.525-533 (Journal article) |
|
6.06 |
No evidence of spread by vegetative means. |
|
|
6.07 |
Fast growing tree species cultivated for showy flowers. [Probably flowers in 2 to 3 years after planting]. |
http://72.14.253.104/search?q=cache:CLotRr7OXOgJ:edis.ifas.ufl.edu |
|
7.01 |
Probably not - no evidence that the propagules have any means of attachment. |
http://hort.ufl.edu/trees/BAUPURA.pdf#search=%22%22bauhinia%20purpurea%22%22 |
|
7.02 |
It is a medium-size multipurpose tree, which besides timber and fuelwood provides fodder, food, tannin and gum The bark, roots and flowers have medicinal properties. B. purpurea is widely planted as an ornamental tree in parks, gardens and homesteads, and along avenues. |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
7.03 |
Probably not- relatively large seeds - 1/2 tp 5/8 inch long, shiny brown. |
Little, E. L. and Wadsworth, F. H. Common Trees of Puerto Rico and the Virgin Island. Volumes 1 and 2. U.S. Department of Agriculture. U.S.Governmet Printing Office. Washington D.C. Vol 2 page 266 |
|
7.04 |
The flowers are followed by 12 inch long slender, brown, flat seedpods which usually persist on the tree throughout the winter, then fall to create a mess to clean up.' [Probably not - no evidence of adaption for wind dispersal - dispersed by gravity]. |
http://hort.ufl.edu/trees/BAUPURA.pdf#search=%22%22bauhinia%20purpurea%22%22 |
|
7.05 |
Probably not - no evidence that the species inhabtis waterways in its natural range. |
|
|
7.06 |
Probably not - fruit is a pod. |
|
|
7.07 |
Probably not - no evidence that the propagules have any means of attachment. |
|
|
7.08 |
Don’t know if dispersed by ungulates. |
|
|
8.01 |
Probably not- relatively large seeds - 1/2 tp 5/8 inch long, shiny brown. |
Little, E. L. and Wadsworth, F. H. Common Trees of Puerto Rico and the Virgin Island. Volumes 1 and 2. U.S. Department of Agriculture. U.S.Governmet Printing Office. Washington D.C. Vol 2 page 266 |
|
8.02 |
(1)Seed storage orthodox. (2)Seed does not store well; sow as soon as possible. [Probably not - but no evidence of seed viability under natural conditions]. |
(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://davesgarden.com/pf/go/2325/index.html |
|
8.03 |
No evidence that the species is being controlled for. |
|
|
8.04 |
(1)Regenerates repidly. (2)Requires pruning to develop strong structure |
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. |
|
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 created 26 December 2006