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

Koelreuteria elegans (Seem.) A.C. Sm. ssp. formosana (Hayata) F.G. Mey. ; flamegold , golden-rain tree, Chinese flame tree
Synonyms: Koelreuteria formosana Hayata; Koelreuteria vitiensis A.C. Sm.; Koelreuteria henryi

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

y

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

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

y

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

y

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

y

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

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

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

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

3

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

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

y

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

y

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

Notes

Source

1.01

no evidence

1.02

(1) "Trees have escaped cultivation and can be seen in many areas invading roadside woodlands. In most years, trees usually survive the cold temperatures in hardiness zone 8B."
(2) "Listed by the Brisbane City Council as a weed of bushland around Brisbane (Csurhes & Edwards, 1998). In Florida it has escaped from cultivation in certain areas (Meyer, 1976)."

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) http://www.hear.org/pier/species/koelreuteri_%20elegans.htm

1.03

no evidence

2.01

Distributional range:
Native: Eastern Asia: Taiwan

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?102682 (21 January 2004)

2.02

2.03

(1)Hardiness Range 9A to 11; In most years, trees usually survive the cold temperatures in hardiness zone 8B. (2)Very tough, drought-tolerant (3)Can tolerate frost, "these trees come from the mountains of Taiwan" [high elevations while also invasive at low elevations in Florida]

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.redwoodbarn.com/trees.html (3)http://www.treedavis.org/w97.html

2.04

Distributional range:
Native: Eastern Asia: Taiwan

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?102682 (21 January 2004)

2.05

(1) Florida, Louisiana, Mississippi, Texas, (2) Hawaii, (3) Argentina

(1) USDA, NRCS. 2002. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
(2) Neal, M.C. (1965) In Gardens of Hawaii. Bernice p. Bishop Museum Special Publicatio 50. Bishop Museeum Press, Honolulu. 924pp. p. 536
(3) Ferrucci, M. S.; Pompert, M. de (1996) New location for cultivated Sapindaceae: Koelreuteria elegans subsp. formosana. (Foreign Title: Nueva cita de Sapindaceae cultivada: Koelreuteria elegans subsp. formosana.) Bonplandia, 1996, Vol. 9, No. 1/2, pp. 25-27, 9 ref.

3.01

"Trees have escaped cultivation and can be seen in many areas invading roadside woodlands. "
Attributes and Features- Naturalizing- Invasive plant

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

3.02

(1)"Seedlings germinate everywhere around this tree creating quite a weed problem - a nightmare actually." (2)A VERY weedy tree. Seedling come up in the landscape by the thousands, requiring constant removal from areas where it is not desired. Not recommended for general use if not ready to pull up seedlings. [landscape/amenity weed]

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://sarasota.extension.ufl.edu/Hort/MG/Golden_Raintree.htm

3.03

no evidence

3.04

(1) "Trees have escaped cultivation and can be seen in many areas invading roadside woodlands. In most years, trees usually survive the cold temperatures in hardiness zone 8B."
(2) "Listed by the Brisbane City Council as a weed of bushland around Brisbane (Csurhes & Edwards, 1998). In Florida it has escaped from cultivation in certain areas (Meyer, 1976)."
(3) on "The Alert List for Environmental Weeds" (4)Florida - Category II - Invasive exotics that have increased in abundance or frequency but have not yet altered Florida plant communities to the extent shown by Category I species. [evidence of environmental problems in multiple geographic locations]

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) http://www.hear.org/pier/species/koelreuteri_%20elegans.htm
(3) http://www.weeds.crc.org.au/documents/weed_watch_vol2_no4.pdf (4)http://www.fleppc.org/

3.05

"Golden rain tree (K. paniculata) should not be planted in Florida (or in similar climates) because it becomes invasive and displaces native plants. The Florida Exotic Pest Plant Council lists golden rain tree as an invader with the potential to disrupt native plant communities." [this information is not accurate - fleppc only lists K. elegans]

http://www.floridata.com/ref/K/koel_p.cfm

4.01

no description of these traits

Neal, M.C. (1965) In Gardens of Hawaii. Bernice p. Bishop Museum Special Publicatio 50. Bishop Museeum Press, Honolulu. 924pp. p. 536

4.02

no evidence

4.03

no evidence

4.04

no evidence [Sapindaceae with saponins?]

http://216.239.57.104/search?q=cache:ws6pAbBSyXMJ:www.hnd.usace.army.mil/techinfo/CPW/PWTB200-1-19/.%255CPWTB%2520200-1-19_AppendixB.pdf+Koelreuteria+elegans+cattle&hl=en&ie=UTF-8

4.05

no evidence

4.06

(1) Pests: Usually none but scales can cause some problems. Diseases: Root rot occurs on old trees. A canker causes dead and sunken areas on the bark. Verticillium wilt can cause decline. [all above pests are generalists]
(2) Jadera haematoloma (no economic importance)
(3) fungi recorded
Armillariella tabescens: FL (generalist)
Bulbouncinula bulbosa: Taiwan (no economic importance)
Cercospora sp.: FL
Corynespora sp.: FL
Fusarium solani: FL (generalist)
Macrophomina phaseolina: FL (generalist)
Phyllosticta sp.: FL
Pythium sp.: FL
Rhizoctonia sp.: FL

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) Carroll, S. P.; Klassen, S. P.; Dingle, H. (1998) Rapidly evolving adaptations to host ecology and nutrition in the soapberry bug. Evolutionary Ecology, 1998, Vol. 12, No. 8, pp. 955-968, 31 ref.
(3) http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm

4.07

Koelreuteria (vomiting, abdominal pain, and in some cases diarrhea) [no evidence that it is consumed]

http://www.minitaly.com/floppy/txt/Plants_and_Cats.htm#Koelreuteria

4.08

Low flammability

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

4.09

Exposure Full sun

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

4.1

"Flamegold is a tough tree which should be grown in full sun on any well-drained soil, in sand, loam or heavy clay, and should receive moderate watering. "; "Soil Condition Loamy, sandy, clay, acidic, neutral, alkaline, tolerates salt, drought tolerant, flood tolerant"

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

4.11

tree

Neal, M.C. (1965) In Gardens of Hawaii. Bernice p. Bishop Museum Special Publicatio 50. Bishop Museeum Press, Honolulu. 924pp. p. 536

4.12

(1)"Seedlings germinate everywhere around this tree creating quite a weed problem - a nightmare actually." (2)A VERY weedy tree. Seedling come up in the landscape by the thousands, requiring constant removal from areas where it is not desired.

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://sarasota.extension.ufl.edu/Hort/MG/Golden_Raintree.htm

5.01

terrestrial

5.02

tree; Sapindaceae

5.03

no evidence

5.04

tree

6.01

"Seedlings germinate everywhere around this tree creating quite a weed problem - a nightmare actually."

6.02

" non-dormant viable seeds of these 3 species would germinate completely within 8 weeks in germination tests. "

Yang, JengChuann; Chen, YuHsin; Lin, TsanPiao (2000) Seed storage behavior of Gordonia axillaris (Boxb.) Dietr., Pistacia chinensis Bunge, and Koelreuteria henryi Dummer. Taiwan Journal of Forest Science, 2000, Vol. 15, No. 1, pp. 91-104, 20 ref.

6.03

no evidence

6.04

no evidence

6.05

small yellow flowers, but morphology and poition of stigma appears to be specialized

http://www.cuyamaca.net/oh170/Plant_TNails_2/Koelrueteria_bipinatta_-_Flower_copy.JPG

6.06

no evidence

6.07

GROWTH RATE: Fast. SIZE: Typically 35-40 feet tall [minimum for a fast growing medium tree]

http://sarasota.extension.ufl.edu/Hort/MG/Golden_Raintree.htm

7.01

"Seedlings germinate everywhere around this tree creating quite a weed problem - a nightmare actually. Trees have escaped cultivation and can be seen in many areas invading roadside woodlands." [wind dispersed fruits can easily be spread along roadsides by vehicles]

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

7.02

an ornamental

7.03

no evidence

7.04

Table 2. "wind dispersal syndrome"

http://hbs.bishopmuseum.org/pdf/op65.pdf

7.05

no evidence

7.06

dry fruit

7.07

no known attaching structure

7.08

no evidence of ingestion

8.01

(1)" Capsules ellipsoidal, the valves rotund to suborbicular (placenta continuous and nonwinged), 3.4-5 (-6) cm long, (2.5-) 3.1-4.6 cm wide, inner side lustrous, reticulate-veined, scattered-pubescent when young, becoming glabrous, deep rose-purple while young, brownish at maturity; styles (1.5-) 2-6 mm long, seeds pyriform to nearly spherical, 5.2-5.5 mm in diameter, black, slightly rugose or smooth.” (Meyer, 1976)" [probably not, relatively large seed] (2)based on photo, two seed per fruit and roughly 100-200 seeds per panicle with roughly 1 panicle per square meter

(1)http://www.hear.org/pier/species/koelreuteri_%20elegans.htm (2)http://aoki2.si.gunma-u.ac.jp/BotanicalGarden/PICTs/taiwan-mokugenji.jpeg

8.02

(1)The effects of moisture content and temperature on the storage behaviour of seeds of Gordonia axillaris, Pistacia chinensis, and Koelreuteria henryi [Koelreuteria elegans var. formosana]were investigated. The germination percentages of these 3 species did not decline after 18-24 months of storage at -20 deg C, 5% moisture content, therefore, confirming their orthodox seed storage behaviour. The optimum seed moisture contents for the storage of seeds of these 3 species at -20 deg C were 5-10%, 4-9%, and 5-10% (fresh weight), respectively. Only seeds of P. chinensis showed slight dormancy; non-dormant viable seeds of these 3 species would germinate completely within 8 weeks in germination tests. After prechilling at 4 deg C for 2 months, the germination percentage of fresh mature seeds of P. chinensis increased but not in the other 2 species. The mean germination times of seeds of G. axillaris and P. chinensis were reduced by 50%by prechilling 8 and 2 months at 4 deg C, respectively. The effect of prechillin

(1)Yang, JengChuann; Chen, YuHsin; Lin, TsanPiao (2000) Seed storage behavior of Gordonia axillaris (Boxb.) Dietr., Pistacia chinensis Bunge, and Koelreuteria henryi Dummer. Taiwan Journal of Forest Science, 2000, Vol. 15, No. 1, pp. 91-104, 20 ref. (2)http://edis.ifas.ufl.edu/ST337

8.03

Table of Current Control Methods for Priority Environmental Weeds: Stem inject with equal parts solution of Glyphosate 360® and water. Other control methods include: Cut stump with equal parts solution of Glyphosate 360® and water. Dig up/hand pull young plants. [herbicide is the major method used to control the species]

http://www.nrm.qld.gov.au/pests/environmental_weeds/pdf/controltable.pdf

8.04

(1) "Root system is a bit coarse resulting in poor root balls in many soils. Regular root pruning during production may enhance the quality of the root ball. Many trees are offered in containers. Those designed to minimize circling roots would be suggested. Be sure to clear all turf away from beneath the branches and mulch to the dripline, especially on young trees, to reduce competition with turf and weeds. This will allow roots to become well established and keep plants healthier." [relatively inactive root system]

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

8.05

no evidence