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

Schefflera arboricola; dwarf umbrella-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

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

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

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

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

n

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

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

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

y

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

y

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

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

8.05

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

y=-1, n=1

Total score:

3

Source

Notes

1.01

no evidence

1.02

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Schefflera+arboricola (10 June 2002)

"naturalized elsewhere " [this source uses the term 'naturalized' loosely to mean 'adopted into cultivation' -- could not find any evidence of naturalization in floras]

1.03

no evidence

2.01

(1)USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Schefflera+arboricola (10 June 2002) (2)http://www.plantscaping.net/medium_light.htm

(1)Distributional range:
Native:
Asia-Temperate: China - Guangdong, Guangxi; Taiwan
Other: naturalized elsewhere (2)Native to: Taiwan

2.02

2.03

http://www.farm-life.com/arbicola/scheffle1.htm

S. arboricola is rather tolerant of a wide variety of growing conditions. The plant toleratesbetween 35 and 105°F. With 77°F the optimum temperature, the best growing temperatures are generally maintained between 65 and 90°F.

2.04

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Schefflera+arboricola (10 June 2002)

Distributional range:
Native:
Asia-Temperate: China - Guangdong, Guangxi; Taiwan
Other: naturalized elsewhere (2)Native to: Taiwan

2.05

(1) Denis, P. (1996) Variety: 'Mme de Smet'. Application no: 94/231. Plant Varieties Journal, 1996, Vol.9, No.1, p.31, 33
(2) Marcelis-Van Acker, C. A. M.; Leutscher, K. J. (1993) Effect of type of cutting on heterogeneity and growth of Rosa hybrida cv. 'Motrea' and Schefflera arboricola cv. 'Compacta'. Scientia Horticulturae, 1993, Vol.54, No.1, pp.59-67, 15 ref.
(3) Gabriels, R.; Verdonck, O.; Mekers, O. (1986) Substrate requirements for pot plants in recirculating water culture. Acta Horticulturae, 1986, No.178, pp.93-99, 11 ref.
(4) Mackroth, K.; Fischer, M. (1986) Greenhouse with quadruple cladding and heat-energy coupling. [FT: Gewächshaus mit Vierfach-Eindeckung und Wärme-Kraft-Kopplung.] Deutscher Gartenbau, 1986, Vol.40, No.37, pp.1688-1690, 6 ref.
(5) Aguilá, J. F.; Grau, J.; Tapia, L.; Caballero, A. (1985) Daily evolution and rates of renewal of CO2 in an iron and glass greenhouse in El Maresme.[FT: Evolución diaria y tasas de renovación del CO2 en invernadero de hierro y vidrio en "El Ma

(1) Australia (2) Nitherland (3) Belgium (4) Germany (5) Spain (6) Denmark (7) Florida, USA

3.01

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Schefflera+arboricola (10 June 2002)

"naturalized elsewhere " [this source uses the term 'naturalized' loosely to mean 'adopted into cultivation' -- could not find any evidence of naturalization in floras]

3.02

no evidence

3.03

no evidence

3.04

http://edis.ifas.ufl.edu/ST586

little invasive potential

3.05

Batianoff, G. N.; Franks, A. J. (1998) Environmental weed invasions on south-east Queensland foredunes. Proceedings of the Royal Society of Queensland, 1998, Vol.107, pp.15-34, 37 ref.

AB: " The most invasive seashore weeds were Asparagus aethiopicus cv. Sprengeri, Bryophyllum spp., Chrysanthemoides monilifera [C. moniliferum ] subsp. rotundata , Gloriosa superba , Lantana camara , Panicum maximum , Schefflera actinophylla , Schinus terebinthifolia [S. terebinthifolius ], Senna pendula var. glabrata and Wedelia trilobata ."

4.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.415

no description of these traits

4.02

no evidence

4.03

no evidence

4.04

no evidence

4.05

no evidence

4.06

http://www.fcprac.ifas.ufl.edu/citrustopics/pest%20control/
Diaprepes/Diaprepes%20Proceedings/simpson.hostplants.htm

DIAPREPES ROOT WEEVIL [generalist]

4.07

Hansen, L.; Boll, P. M. (1986) The polyacetylenic falcarinol as the major allergen in Schefflera arboricola. Phytochemistry, 1986, Vol.25, No.2, pp.529-530, 23 ref.

AB: Members of the genus Schefflera, which are popular in Europe as ornamental plants, have been reported to cause allergic contact dermatitis. The major allergen isolated from the ether extract of fresh leaves and stems of S. arboricola was identified as falcarinol, heptadeca-1,9(Z )-dien-4,6-diyn-3-ol. The isolation of (E )--farnesene, phytol and 24-ethylcholesta-5,22(E )-diene-3-ol (poriferasterol) is also reported. [rare, with minor symptoms?]

4.08

unlikely, thick, lush leaves in moist habitats

4.09

(1)Sawwan, J. S.; Ghunem, R. S. (1999) Light acclimatization of Schefflera arboricola . Advances in Horticultural Science, 1999, Vol.13, No.4, pp.151-155, 16 ref.
(2)Schiefthaler, U.; Russell, A. W.; Bolhàr-Nordenkampf, H. R.; Critchley, C. (1999) Photoregulation and photodamage in Schefflera arboricola leaves adapted to different light environments. Australian Journal of Plant Physiology, 1999, Vol.26, No.5, pp.485-494, 51 ref. (3)http://edis.ifas.ufl.edu/ST586

(1) AB: S. arboricola is an important house plant which is greatly affected by low light levels typical in many houses. Acclimatization to low light levels during production is an important step to get good quality plants. This study was conducted to investigate the effect of acclimatization on subsequent performance of plants in a simulated interior environment. Plants (from a commercial nursery or grown from cuttings in the glasshouse) were exposed to zero, 40, 60 or 80% light exclusion for zero, 4, 8 or 12 weeks, then held for 12 weeks in a simulated interior environment (photosynthetic photon density of 3-6 micro molm-2s-1 and 25 plus or minus 1 deg C). At the end of the acclimatization period, data on chlorophyll content, and leaf surface area, weight and thickness were recorded. In the simulated interior environment, number of dropped leaflets were recorded weekly, chlorophyll content was measured at the end of this period, and plants were visually graded on a scale of 1 (poor)-10 (excellent). Chloroph

4.1

(1)Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.416 (2)http://www.growinglifestyle.com/article/s0/a83162.html (3)http://edis.ifas.ufl.edu/ST586

(1)"moist but well-drained soils are prefered " (2)Not particular about the type of soil, however it should be well drained and slightly alkaline. (3)does best on light, sandy, well-drained soils

4.11

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.415

"shrub to 4 m high"

4.12

no evidence

5.01

terrestrial

5.02

shrub; Araliaceae

5.03

no evidence

5.04

shrub

6.01

no evidence

6.02

Rucker, K. (1978) A new schefflera as a foliage plant. [FT: Eine neue Schefflera fur das Grunpflanzensortiment. Deutscher Gartenbau, 1978, Vol.32, No.1, p.9

AB: Schefflera arboricola is similar to S. actinophylla but has narrower and smaller pinnate leaves and less woody stems. Plants have no rest period. In winter a growing temperature of 18 deg C is recommended in view of limited light (low temperatures such as 12 deg C cause defoliation). Normally the plant is propagated from seeds and 3 seedlings are grown per pot. Propagation by cutting requires a high soil temperature. Both species are suited for hydro-culture.

6.03

no evidence

6.04

no evidence

6.05

http://www.mcgerik.com/plants/schefflera.shtml

Flowers are greenish yellow near branch tips [suggests bees or flies]

6.06

no evidence

6.07

no evidence

7.01

no evidence

7.02

Poole, R. T.; Conover, C. A. (1983) Influence of simulated shipping environments on foliage plant quality. HortScience, 1983, Vol.18, No.2, pp.191-193, 11 ref.  

AB: Simulated shipping of Chrysalidocarpus lutescens, Dracaena marginata, Ficus benjamina and Schefflera arboricola for 7, 14, 21 or 28 days at 10, 13, 16 or 19 deg C indicated long-term shipping to be possible while maintaining plant quality. Schefflera shipped best at 10 deg , Ficus at 10 or 13 deg and Chrysalidocarpus and Dracaena at 13, 16 or 19 deg . Simulated shipping durations of up to 21 days were obtained on all species without significant loss of quality, and 28-day durations were possible at selected temperatures without severe quality reductions.

7.03

no evidence

7.04

no evidence

7.05

no evidence

7.06

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.415

"fruit a small orange drupe, infrequently in cultivation"

7.07

no evidence

7.08

dispersed by birds

8.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.415

"fruit a small orange drupe, infrequently in cultivation"

8.02

no evidence

8.03

no evidence

8.04

http://www.evergrowing.com/HousePlantTV/arboricola.htm

PRUNING: It is O.K. to get radical, it will grow back.

8.05

no evidence