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

Leptospermum scoparium (broom teatree)

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

1

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

n

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

y

4.01

Produces spines, thorns or burrs

y=1, n=0

y

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

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

y

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

3

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

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

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

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:

3

Source

Notes

1.01

Dawson, M. 1997. A history of Leptospermum scoparium in cultivation - Part 1. Discoveries from the wild. New Plantsman, 1997, Vol.4, No.1, pp.51-59, abstract

"It is highly polymorphic, and plants producing white-, red-, pink- and double-flowers have been found in the wild. Some 150 cultivars of L. scoparium have been named of which >70 are still cultivated".

1.02

Wagner, Warren L., Derral R. Herbst and S.H. Sohmer. 1990. Manual of the flowing plants of Hawai'i. University of Hawai'i Press, Honolulu. p. 963.

listed as naturalized in Hawaii

1.03

no evidence

2.01

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

(1) Species is native to New Zealand and Tasmania. (2)native toAustralia (New Wales, Victoria, Tasmania), New Zealand

2.02

2.03

(1) Plant Master 5.5. California Edition.1999. Acacia Software, Westlake Village, California. (2) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7 (3) Smith, Clifford W. 1985. Impact of alien plants on Hawai'i's native biota. In: Charles P. Stone and J. Michael Scott, eds.. Hawai‘i’s Terrestrial Ecosystems: Preservation and Management. Cooperative National Park Resources Studies Unit, University of Hawaii, Manoa. p. 193

(1) based on "flowering tea tree" USDA Zones 9-10 ; New USDA Temp Zones 9b-11a; (2)based on "Helen Strybing" 8B to 11 (3) In Hawai’i, it is found in mesic habitats between 300-700 m elevation" (Smith, 1985).

2.04

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

(1) Species is native to New Zealand and Tasmania. (2)native toAustralia (New Wales, Victoria, Tasmania), New Zealand

2.05

sold widely in nurseries in Britian, Germany, Australia, and elsewhere

3.01

Wagner, Warren L., Derral R. Herbst and S.H. Sohmer. 1990. Manual of the flowing plants of Hawai'i. University of Hawai'i Press, Honolulu. p. 963.

listed as naturalized in Hawaii, S african fymbos

3.02

Mohan, E.; Mitchell, N.; Lovell, P. 1984.Seasonal variation in seedfall and germination of Leptospermum scoparium (manuka). New Zealand Journal of Botany, 1984, Vol.22, No.1, pp.103-108. (p.103)

"It colonize cleared and burnt ground and form part of the natural succession to native forest "

3.03

3.04

Syrett, P.; Hill, R. L.; Jessep, C. T. 1985. Conflict of interest in biological control of weeds in New Zealand.Proceedings of the VI International Symposium on Biological Control of Weeds., 1985, pp.391-397, abstract

"The role that conflicts of interest have played in the development of projects for biological control of weeds in New Zealand in the past is discussed. Particular reference is made to projects for control of Rubus fruticosus, Rosa rubiginosa, Leptospermum scoparium and Ulex europaeus." [native to New Zealand but considered as a weed ]

3.05

http://www.arc-ovi.agric.za/v-arcroot/institutes/ppri/main/divisions/weedsdiv/fynboselectronic/myrtac.htm

Leptospermum laevigatum is INVASIVE PLANT IN FYNBOS

4.01

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

leaf point pungent

4.02

no evidence

4.03

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

4.04

Clark, D. A.; Lambert, M. G. 1989.The role of goats in New Zealand hill country farming.Proceedings of the XVI International Grassland Congress, 4-11 October 1989, Nice, France., 1989, pp.1359-1360, abstract

"Thistles (Cirsium spp. Carduus tenuiflorus ), manuka (Leptospermum scoparium ) and gorse (Ulex europaeus ) were readily grazed by goats but not by sheep."

4.05

Clark, D. A.; Lambert, M. G. 1989.The role of goats in New Zealand hill country farming.Proceedings of the XVI International Grassland Congress, 4-11 October 1989, Nice, France., 1989, pp.1359-1360, abstract

"Thistles (Cirsium spp. Carduus tenuiflorus ), manuka (Leptospermum scoparium ) and gorse (Ulex europaeus ) were readily grazed by goats but not by sheep."

4.06

no evidence

4.07

no evidence

4.08

no evidence

4.09

4.1

Berninger, E.1992. Diversity of tolerance to soil pH in Leptospermum scoparium (J. R. and G. Forst) populations from New Zealand.Acta Horticulturae, 1992, No.320, pp.49-55, abstract

This shrub is endemic to New Zealand and is widespread on crystalline, acidic soils (pH less than or equal to 6). Introduced in 1987, selected maternal progenies of various latitude and altitude sources displayed severe chlorosis on the neutral to alkaline alluvial soil of southern France (pH 8 to 8.3), probably due to active lime, and iron blockage. Some progenies showed an unexpected variation for alkaline soil tolerance. Clones from cuttings of tolerant mother plants were planted in alkaline soil in 1989 and performed well for 3 years.

4.11

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

shrub

4.12

Smith, Clifford W. 1985. Impact of alien plants on Hawai'i's native biota. In: Charles P. Stone and J. Michael Scott, eds.. Hawai‘i’s Terrestrial Ecosystems: Preservation and Management. Cooperative National Park Resources Studies Unit, University of Hawaii, Manoa. p. 193.

"This small, scrubby tree forms thickets which crowd out other plants.

5.01

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

shrub

5.02

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

shrub

5.03

no evidence

5.04

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

6.01

no evidence

6.02

Mohan, E.; Mitchell, N.; Lovell, P. 1984.Seasonal variation in seedfall and germination of Leptospermum scoparium (manuka). New Zealand Journal of Botany, 1984, Vol.22, No.1, pp.103-108, abstract

" Viable seed was shed throughout the year. "

6.03

6.04

6.05

no evidence

6.06

no evidence

6.07

Dr R. Criley, Dept. of Horticulture, University of Hawaii Manoa

7.01

no evidence

7.02

as oramental

7.03

no evidence

7.04

Neal, Marie C. 1965. In Gardens of Hawaii. Bernice P. Bishop Museum Special Publication 50, Bishop Museum Press. p. 642.

Seeds are dispersed by wind.

7.05

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

7.06

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

dry fruit

7.07

Harden, G. J (ed.) (1991). Flora of New South Wales Vol.2. New South Wales University Press, Kensington, Australia 574pp. (p.162)

7.08

not bird dispersed

8.01

Mohan, E.; Mitchell, N.; Lovell, P. 1984.Seasonal variation in seedfall and germination of Leptospermum scoparium (manuka). New Zealand Journal of Botany, 1984, Vol.22, No.1, pp.103-108. (p.106)

Viable seed was shed throughout the year. 111-334 seeds/daym2

8.02

Mohan, E.; Mitchell, N.; Lovell, P. 1984. Environmental factors controlling germination of Leptospermum scoparium (manuka). New Zealand Journal of Botany, 1984, Vol.22, No.1, pp.95-101, abstract

"There was no evidence of dormancy and it is likely that the major 'seed bank' is present in the unshed capsules rather than on the ground surface."

8.03

Mason, G. W. 1973. A review of chemical control of brushweeds on agricultural land in New Zealand. Proceedings of the 4th Asian-Pacific Weed Science Society Conference, Rotorua, 1973., 1973, pp.339-346, abstract

The widespread use of herbicides as part of brushweed control programmes is outlined. The mixing of additional herbicides with 2,4,5-T in the last decade has improved control to include a wider range of species for a longer period of time. Picloram + 2,4,5-T has proved very effective against Ulex europaeus, Cytisus spp., Rubus spp. and Rosa rubiginosa, the main introduced brushweeds. Leptospermum scoparium is the most important indigenous species of unploughable and less fertile hill country and is best controlled by 2,4,5-T.

8.04

no evidence

8.05

no evidence