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

Bauhinia × blakeana Dunn = [B. purpurea × B. variegata]; Hong Kong Orchid Tree

Answer

1.01

synonyms: Crescentia pinnata Jacq.; Kigelia pinnata (Jacq.) DC.

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

y

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

y

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

n

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

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

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

n

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

n

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

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

8.05

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

y=-1, n=1

Total score:

-7

Notes

Source

1.01

a hybrid producing no fruit, only propagated vegetatively, by people [but both parents are wild and the hybrid is not domesticated]

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

1.02

no evidence

1.03

no evidence

2.01

Native Habitat: China

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

2.02

[origin vague]

2.03

(1)Hardiness Range 9B to 11 (2)Elevaton 0-1800 m [based on B. variegata]

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://ecocrop.fao.org/

2.04

Native Habitat: China

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

2.05

(1) Florida, (2) Brasil, (3) Hawaii (4)caribbean

(1) USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
(2) Machado, J. W. B.; Alencar, F. O. C. C. de; Moreira L. Filho, R.; Araújo, H. A. de (1982) Notes on the vegetative propagation of Bauhinia blakeana. [FT: Notas sobre a propagação vegetativa de Bauhinia blakeana Dunn.] Brasil Florestal, 1982, Vol.12, No.52, pp.55-58, 7 ref.
(3) Neal, M.C. (1965) In Gardens of Hawaii. Bernice P. Bishop Museum Special Publicatio 50. Bishop Museeum Press, Honolulu. 924pp. (4)http://www.caribbeangardens.com/Plants_Animals/plant%20files/hong%20kong%20orchid.htm

3.01

no evidence

3.02

no evidence

3.03

no evidence

3.04

no evidence

3.05

Bauhinia variegata is an environmental weed of Florida

FLEPPC Florida Exotic Pest Plant Council. 1999. Invasive plant list (http://www.fleppc.org/, 19 October 1999). Florida Exotic Pest Plant Council.

4.01

Trunk has no thorns

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

4.02

no evidence

4.03

no evidence

4.04

Leaves used for animal fodder [based on B. variegata]

http://ecocrop.fao.org/

4.05

no evidence

4.06

(1) Pests: Borers, caterpillars, mites. [generalist] Diseases: Leaf spot [don't know its identity], leaf scorch diseases [noninfectious]
(2) Phomopsis bauhinicola sp. nov. on Bauhinia blakeana [no known economic importance]

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) Xiang MeiMei; Jiang ZiDe; Qi PeiKun (2003) New species and new records of Phomopsis on Caesalpiniaceae from China. Mycosystema, 2003, Vol.22, No.3, pp.354-356, 1 ref.

4.07

no evidence

4.08

"Low flammability"

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

4.09

(1) Exposure Partial shade or partial sun to full sun. Hong Kong Orchid Tree grows in full sun on well-drained soil.
(2) Sun Exposure: Full Sun, Sun to Partial Shade, Light Shade

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) http://plantsdatabase.com/go/53664/index.html

4.1

Soil Condition Loamy, sandy, clay, acidic, neutral, slightly alkaline, tolerates salt, drought tolerant. Hong Kong Orchid Tree grows in full sun on well-drained soil.

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

4.11

"Growing 20 to 40 feet in height, Hong Kong Orchid-Tree creates a rounded, spreading canopy"

http://hort.ifas.ufl.edu/trees/BAUBLAA.pdf

4.12

"Growing 20 to 40 feet in height, Hong Kong Orchid-Tree creates a rounded, spreading canopy"

http://hort.ifas.ufl.edu/trees/BAUBLAA.pdf

5.01

terrestrial

5.02

tree; Caesalpiniaceae

5.03

Like most other legumes, the orchid tree has a symbiotic relationship with Rhizobium bacteria. The bacteria form root nodules and extract atmospheric nitrogen which enables the Hong Kong orchid tree to grow in poor soils.

5.04

tree Height : 20 to 40 ft.

6.01

an artificial hybrid lacking a native range

http://hort.ifas.ufl.edu/trees/BAUBLAA.pdf

6.02

a sterile hybrid "These flowers are sterile and will not set seed"

http://hort.ifas.ufl.edu/trees/BAUBLAA.pdf

6.03

don't know its ability to be a pollen donor, however, it is a sterile hybrid that doesn't produce fruit

6.04

a sterile hybrid

6.05

Butterfly attractor. [but irrelevant because sterile]

http://trees-seeds.com/seeds.htm

6.06

no evidence

6.07

a sterile hybrid

7.01

a sterile hybrid

7.02

"This is often the Orchid-Tree of choice for planting in urban landscapes."

http://hort.ifas.ufl.edu/trees/BAUBLAA.pdf

7.03

a sterile hybrid

7.04

a sterile hybrid

7.05

a sterile hybrid

7.06

a sterile hybrid

7.07

a sterile hybrid

7.08

a sterile hybrid

8.01

a sterile hybrid

8.02

a sterile hybrid

8.03

no evidence

8.04

When young, the Hong Kong Orchid trees are usually misshapen and sprawly. It is a good idea to prune young trees so they will develop a better canopy. If pruned properly they will produce a rounded, spreading head.

http://coop.co.pinellas.fl.us/TimeTweb/2002/april02/apropal.htm

8.05

no evidence