Pacific Island Ecosystems at Risk (PIER)


Callistemon citrinus


RISK ASSESSMENT RESULTS: Low risk, score: 0


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.

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

Callistemon citrinus (C. lanceolatus (Sm.) Sweet, Metrosideros citrina Curtis [basionym], M. lanceolata Sm. ); crimson bottlrbush, Australian bottlebrush

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

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

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

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

n

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

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

y

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

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

y

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

n

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

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:

0

Supporting data:

Source

Notes

1.01

http://farrer.riv.csu.edu.au/ASGAP/c-cit.html

The species has been responsible for may of the cultivars that are seen in gardens, sometimes as hybrids with other Callistemon species. Most of these cultivars have arisen as chance seedlings rather than by deliberate hybridisation. Some of the better known cultivars of C.citrinus are "Mauve Mist" (mauve), "Burgundy" (purple-red), "White Anzac", "Endeavour" (red) and "Reeves Pink" (pink). 

1.02

no evidence

1.03

no evidence

2.01

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/cgi-bin/npgs/html/taxon.pl?8561 (25 September 2003)

Distributional range:
Native: Australasia: Australia - New South Wales [e.], Queensland [e.], Victoria [e.]

2.02

2.03

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.capricornica.com/plants/cal_citr.htm (3)http://www.forests.qld.gov.au/qts/treetext.html

(1)Hardiness Range 8B to 11 (2)heath and swampland, sunny creek banks. (3)Frost tolerant

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/cgi-bin/npgs/html/taxon.pl?8561 (25 September 2003)

Distributional range:
Native: Australasia: Australia - New South Wales [e.], Queensland [e.], Victoria [e.]

2.05

(1) Balakrishna, M. and S. K. Bhattacharjee (1991). "Studies on propagation of ornamental trees, through stem cuttings." Indian Journal of Horticulture 48(1): 87-94. (2) USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

(1) India, (2) Louisiana, Puerto Rico in USA

3.01

no evidence

3.02

no evidence

3.03

no evidence

3.04

no evidence

3.05

no evidence

4.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.144 p.101

no description of these taits

4.02

http://www.zenecaagproducts.com/media/article.asp?article_id=125

Calliston corn herbicide, a new post-emergence product that controls nearly all the major broadleaf weeds in corn. Developed from a naturally occurring herbicide in the Callistemon citrinus plant, Callisto brings a new mode of action to broadleaf weed control in corn. It offers post-emergence and residual control of the toughest broadleaf weeds in corn, excellent crop safety, a favorable environmental profile, a wide window of application, and a low use rate. [allelopathic potential?; leaves have citrus scent]

4.03

no evidence

4.04

http://www.mydeergarden.com/Plant_DB/LISTresults.asp?Genus=Callistemon&Species=citrinus

no evidence 'Deer Resistance: Sometimes eaten.'

4.05

http://www.mydeergarden.com/Plant_DB/LISTresults.asp?Genus=Callistemon&Species=citrinus

no evidence 'Poisonous to Deer: Generally Not'

4.06

Polizzi, G. (1996) Myrtaceae, natural hosts of Cylindrocladium scoparium . [FT: Mirtacee, ospiti naturali di Cylindrocladium scoparium .] Informatore Fitopatologico, 1996, Vol.46, No.2, pp.59-64, 21 ref.

AB: The occurrence and severity of C. scoparium infections in some ornamental plant nurseries were studied in Calabria, southern Italy, and Sicily in 1993-94. Over 300 species belonging to 74 families were monitored and the fungus, only recently observed in Italy, was isolated exclusively from myrtaceous plants. The pathogen caused serious and widespread defoliation, die-back of shoots and leaf spots on honey myrtle plants (Melaleuca hypericifolia ), 'variegated' iron tree (Metrosideros robustus [M. robusta ]) and myrtle (Myrtus communis ). Leaf spots and shoot die-back following pruning wounds were observed on Callistemon citrinus . In addition, leaf spots were detected on Murray red gum (Eucalyptus rostrata [E. camaldulensis ]) and occasionally on Tasmanian blue gum (E. globulus ). This is believed to be the first report of C. scoparium on the genus Metrosideros . The high number of fungal propagules collected in the soil samples mixed with infected fallen leaves underline the importance of removing plant

4.07

no evidence

4.08

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

"Low flammability"

4.09

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) http://hort.ifas.ufl.edu/trees/calcita.pdf

(1) Exposure: Full sun; (2)Light requirement: tree grows in full sun

4.1

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2)http://hort.ifas.ufl.edu/trees/calcita.pdf (3)http://users.tpg.com.au/users/palessi/calliste.htm

(1) Soil Condition Loamy, sandy, clay, acidic, neutral, slightly alkaline, tolerates salt, drought tolerant,
(2) Soil tolerances: clay; loam; sand; acidic; well-drained (3)Sandy To Clay Soils

4.11

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.144 p.101

tree

4.12

no evidence

5.01

terrestrial

5.02

tree, Myrtaceae

5.03

no evidence

5.04

tree

6.01

http://farrer.riv.csu.edu.au/ASGAP/c-cit.html

Conservation Status: Not considered to be at risk in the wild.

6.02

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.144 p.102

"propagate by seeds, usually or by cuttings or air alyering"

6.03

http://farrer.riv.csu.edu.au/ASGAP/APOL21/mar01-2.html

'Because individual species of Callistemon come in a number of forms and hybridise so readily, you can't be sure seed grown callistemons will be the same as the parent plant. So if you want to reproduce an exact replica of a particular Callistemon, it is essential you grow your new Callistemon from cutting material and not from seed. ... The species of Callistemon that most commonly are alleged to have been involved in producing hybrids are the commonly grown C.citrinus and C.salignus (originating mainly from New South Wales), C.polandii (Queensland) and, of course, particularly the many forms of C.viminalis (Queensland).'

6.04

no evidence

6.05

(1) Kumar, J.; Kashyap, N. P. (1996) Diversity of bee flora in lower Kullu Valley, Himachal Pradesh and its impact on honey production. Indian Bee Journal, 1996, Vol.58, No.3, pp.131-134
(2) Gupta, J. K.; Kumar, J. (1993) Bottle brush Callistemon lanceolatus DC (Myrtaceae) nectar: amount, type of nectar sugars and honeybee foraging. Apidologie, 1993, Vol.24, No.6, pp.564-568

(1) AB: "A total of 38 plant species were recorded as nectar and/or pollen sources for Apis mellifera . Main nectar sources in the summer were Callistemon citrinus , Trifolium repens , Eucalyptus spp., Sapindus mukorossi and Olea ferruginea [O. cuspidata] "
(2) AB: "Honey bees (Apis mellifera ) harvested approximately 90% of the sugar produced by the flowers. "

6.06

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

"Suckers from the trunk need to be removed periodically to maintain tree form. ' [not fragmentation]

6.07

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

Growth rate: medium [minimum for a small tree with medium growth rate]

7.01

no evidence

7.02

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.144 p.101

"widely cultivated in tropical to warm temperate regions for its red flowers"

7.03

no evidence

7.04

http://www.nzseeds.co.nz/seed_list/Callistemon_citrinus..html

Approximate viable seed per gram >1,000.

[probably yes, very small seeds]

7.05

no evidence

7.06

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.144 p.101

"fruit a small, sessile, woody subglobose capsule 5-7mm long."

7.07

no evidence

7.08

no evidence of being ingested

8.01

http://www.nzseeds.co.nz/seed_list/Callistemon_citrinus..html

Approximate viable seed per gram >1,000.
[probably yes, very small seeds]

8.02

(1) Vinay Kumar; Charan Singh; Kukreti, M. C. (2000) Studies on seed germination of twenty one tree species from central Himalaya. Indian Journal of Soil Conservation, 2000, Vol.28, No.1, pp.54-57, 11 ref.

(1) AB: "The paper deals with the seed germination under laboratory conditions of 21 tree species occurring in Central Himalaya (including C. citrinus) . None of the species showed seed dormancy. [lacks dormancy] 

8.03

no evidence of being controlled

8.04

(1)Whelan, R. J.; Brown, C. L. (1998) The role of Callistemon fruits and infructescences in protecting seeds from heat in fires. Australian Journal of Botany, 1998, Vol.46, No.2, pp.235-239, 17 ref. (2)http://www.rosedownmill.freeserve.co.uk/bottlebrush.html (3)http://farrer.riv.csu.edu.au/ASGAP/callistn.html

(1) A number of Australian plant species tolerate fires because seeds are protected in woody fruits and are released after fire, but there is little information about the role of the fruit, or a collection of fruits, in protecting seed from the heat of a fire. This study examined the effects of various temperatures applied to infructescences of Callistemon citrinus on seed germination. The protective role of the dense collection of fruits in maintaining seed viability was tested by experimentally 'thinning' infructescences before heating. Heating of infructescences significantly increased the percentage of seeds germinating from less than 20% at room temperature to over 35% at 200 deg C, but caused a decline with further temperature increase to 800 deg C. There was a slight but statistically significant increase in the percentage germination of seeds from thinned infructescences. Increased germination following exposure to high temperature may be a way for a plant to synchronize germination after high-intensi

8.05

no evidence


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