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

Mimosa pigra (catclaw mimosa, black mimosa)

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

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

y

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

y

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

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

y

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

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

y

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

1

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

n

7.05

Propagules water dispersed

y=1, n=-1

y

7.06

Propagules bird dispersed

y=1, n=-1

n

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

y

7.08

Propagules survive passage through the gut

y=1, n=-1

y

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

y

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

y

8.05

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

y=-1, n=1

Total score:

25

Notes

Source

1.01

No evidence of vegetative spread in the wild.

1.02

Introduced and invasive in Australia, Thailand and Florida

http://plants.ifas.ufl.edu/invasivesbook2.pdf

1.03

No evidence

2.01

Origin - Central America. 'Widespread throughout the tropics (Lonsdale 1992).'

http://plants.ifas.ufl.edu/invasivesbook2.pdf

2.02

Introduced and invasive in Australia, Thailand and Florida

http://plants.ifas.ufl.edu/invasivesbook2.pdf

2.03

(1)Habitat/ecology: Wet places in the humid and subhumid tropics. Favors climates with a dry season. (2)Mimosa can survive both a seven month dry season and flooding in the wet season. … Mimosa favors a wet-dry tropical climate and would probably not be a major problem in regions with an annual rainfall of less than 750 mm or greater than 2250 mm, except in cases of clear cutting. (3) '... grows at elevations from near sea level to 700 m.' (4)Its favoured habitat is around water and on floodplains. In its native habitat:its natural habitat is mainly marginal areas of canals, rivers and lakes [naturalized plants appear to be restricted to flood planes, river banks and seasonal wetlands]

(1)http://www.hear.org/pier/species/mimosa_pigra.htm (2)http://www.hort.agri.umn.edu/h5015/99papers/marko.htm (3)http://216.239.57.104/search?q=cache:V7pAWzp1XQIJ:www.fs.fed.us
/global/iitf/pdf/shrubs/Mimosa%2520pigra.pdf+Mimosa+pigra&hl=en&ie=UTF-8 (4)http://ecocrop.fao.org/

2.04

Origin - Central America. 'Widespread throughout the tripics (Lonsdale 1992).' Introduced and invasive in Australia, Thailand and Florida

http://plants.ifas.ufl.edu/invasivesbook2.pdf

2.05

(1)Introduced and invasive in Australia, Thailand and Florida (2)Introduced to Pacific Islands.

(1)http://plants.ifas.ufl.edu/invasivesbook2.pdf (2)http://www.hear.org/pier/species/mimosa_pigra.htm

3.01

Introduced and invasive in Australia, Thailand and Florida

http://plants.ifas.ufl.edu/invasivesbook2.pdf

3.02

It also restricts access to waterways for humans, particularly fishermen. … In Thailand it interferes with irrigation systems (sediment accumulation) and access to electric power lines and is a safety hazard along roads.

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

3.03

(1) 'Mimosa pigra L. (Mimosaceae) poses a tremendous threat to agriculture, the conservation of wetlands and land use practices of the Aboriginal people of Australia (Braithwaite et al. 1989).' (2)In Australia M. pigra poses a threat to the cattle industry as it invades buffalo pasture.

(1)http://www.hort.agri.umn.edu/h5015/99papers/marko.htm (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

3.04

'Emerged as a serious weed of wetlands in the 1970s in Australia and Thailand (Lonsdale 1992). By the late 1980s in Australia had formed dense thickets covering some 800 km2 (over 30 mi2) in floodplains and swamp forests, with infestations doubling in size each year (Braithewaite et al 1989). Introduced to FLorida before 1953 ... Large infestation in Florida fiest noted in 1985 (Nall et al. 1986.) Infested natural areas now totaling nearly 400 ha (1000 acres) in Broward, Palm Beach, Martin, St Lucie and Highland counties, including shoreling of the loxahatchee River (Sutton et al. 1994). ...'

http://plants.ifas.ufl.edu/invasivesbook2.pdf

3.05

(1) 'Mimosa pigra is closely related to Mimosa pudica (common sensitive plant) which is also adeclared noxious weed in the Northern Territory.' (2) Mimosa pudica is listed as a principal weed in India, Indonesia, Australia, Malaysia, Mexico, Nigeria and Phillipines.

(1)http://216.239.57.104/search?q=cache:GTZGNQPx2BEJ:www.nt.gov.au
/dbird/dpif/pubcat/agnotes/weeds/466.pdf+Mimosa+pigra&hl=en&ie=UTF-8 (2)Holm et al. 1997. An Electronic Atlas of Weeds and Invasive Species. CD-ROM database. Version 1.

4.01

Sprawling often thicket-forming shrub to 6 m (20 ft) tall, with hairy stems bearing numerous recurved prickles to 7 mm (0-3 in) long.

http://plants.ifas.ufl.edu/invasivesbook2.pdf

4.02

No evidence

4.03

No evidence

http://www.omnisterra.com/bot/pp_home.cgi

4.04

'The impalatability of leaves to mammalian herbivores (Lonsdale et al. 1995) and high reproductive output will continue to make mimosa a noxious species in areas it invades.'

http://www.hort.agri.umn.edu/h5015/99papers/marko.htm

4.05

No evidence

4.06

(1)The following fungi were listed to be associated with M. pigra: Botryodiplodia theobromae: Cuba - 8361
Diabole cubensis: Cuba - [only known from Mimosa pigra]
Microstroma ruizii-belinii: Mexico - [only known from Mimosa pigra]
Mycosphaerella mimosae-pigrae: Mexico - [only known from Mimosa pigra]
Phomopsis sp.: Venezuela - 8361
Sphaerulina mimosae-pigrae: Brazil; Colombia; Mexico; Trinidad & Tobago -[only known from Mimosa pigra]
Uromycladium cubense: Cuba - [only known from Mimosa pigra]
(2)Fungus Botryodiplodia theobromae - Common Host:
American Sycamore Plantanus occidentalis
Significance: Branch and stem cankers of sycamore are a common, readily visible, and sometimes lethal problem in many parts of Florida. Cankers are usually most prevalent and serious on trees which have been injured, by construction for example, or trees which have been exposed to certain environmental stresses such as extreme temperatures or drought. Many fungi are capab

(1)http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm (2)http://www.fl-dof.com/Pubs/Insects_and_Diseases/td_hsd_cankers_of_sycamore.htm

4.07

The roots are irritant (Irvine 1961). [root not likely to be encountered by public]

http://bodd.cf.ac.uk/index.html

4.08

(1) 'Because there is little grassy understorey in thickets of M. pigra, it is difficult to destroy infestations with fire without applying fuel such as gelled gasoline from aircraft. Follow-up control must then be carried out, because, although seeds on the soil surface are destroyed, germination of seeds from the seed bank, within 5cm of the soil surface, is enhanced. (FAO).' (2)Following natural fires the plants resprout freely. [don't know if it is highly flammable -- controled burns often use diesel gels to promote the spread of fire]

(1)http://www.hear.org/pier/species/mimosa_pigra.htm (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

4.09

(1) 'Although adapted to seasonally flooded habitats M. pigra can regenerate under some degree of canopy cover.' (2)requires very bright sunlight

(1)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm (2)http://ecocrop.fao.org/

4.1

(1) 'Mimosa does not appear to grow preferentially in any soil type, but is found most commonly in floodplains and riverbanks within soils ranging from black cracking clays to sandy clays to coarse siliceous river sand.' (2)It does not appear to have any soil type preferences, but is more commonly found in moist situations such as floodplains and river banks.

(1)http://www.hort.agri.umn.edu/h5015/99papers/marko.htm (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

4.11

Not a climber - a shrub

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

4.12

'Forms dense, impenetrabale thickets in wet areas, but will also grow in drier habitats (Miller and Tjitrosoedirdjo1992).'

http://plants.ifas.ufl.edu/invasivesbook2.pdf

5.01

Terrestrial

5.02

Sprawling often thicket-forming shrub to 6 m (20 ft) tall, with hairy stems bearing numerous recurved prickles to 7 mm (0-3 in) long.

http://plants.ifas.ufl.edu/invasivesbook2.pdf

5.03

"Mycorrhizae have been found associated with few strains of Rhizobium. However these associations are rare and it is not clear how important a source of nitrogen they are to populations of M. pigra. "

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

5.04

Sprawling often thicket-forming shrub to 6 m (20 ft) tall, with hairy stems bearing numerous recurved prickles to 7 mm (0-3 in) long.

http://plants.ifas.ufl.edu/invasivesbook2.pdf

6.01

In Costa Rica M. pigra is probably much more common now than prior to European colonisation. Its seeds appear to be spread by road construction equipment and thus the plant is typical of roadsides.

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

6.02

(1) 'Germinates best on damp, not dry or saturated soil; will germinater under water but remains slow in its growth until emersed. Germinates year-round (Sutton and Langeland 1993), with a small percentage (6-8% in Florida studies) of seed crop not germinating but remaining viable as a log-term seed bank ) Lonnsdale 1992, Sutton and Langeland 192). (2)Seeds generally germinate when they are first wetted and the germination rate is high.

(1)http://plants.ifas.ufl.edu/invasivesbook2.pdf (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

6.03

Don’t know

6.04

'In Australia it has been suggested that most of the seeds are produced by autogamy, although wind pollination can not be ruled out. '

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

6.05

'The bee-pollinated inflorescences, containing up to 100 flowers, are spherical, pink and last one day'

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

6.06

The shrub does not naturally reproduce vegetatively.

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

6.07

(1)Maximum age is about 5 years. … Flowering may start within a year of germination. (2)Black mimosa grows rapidly and can begin producing seed in as little as 3 months after emergence.

(1)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm (2)http://216.239.57.104/search?q=cache:V7pAWzp1XQIJ:www.fs.fed.us
/global/iitf/pdf/shrubs/Mimosa%2520pigra.pdf+Mimosa+pigra&hl=en&ie=UTF-8

7.01

Probably yes - 'In Costa Rica M. pigra is probably much more common now than prior to European colonisation. Its seeds appear to be spread by road construction equipment and thus the plant is typical of roadsides.'

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

7.02

(1)It has been used as green manure and cover crop and is used as firewood and bean poles in Thailand. Utilized against snake bites. (2)It has been introduced into a number of other tropical countries as an ornamental or a cover crop where it is now a serious weed

(1)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm (2)http://216.239.57.104/search?q=cache:jTQQ2OQKEm4J:www.nrm.qld.gov.au
/factsheets/pdf/pest/PP25.pdf+Mimosa+pigra&hl=en&ie=UTF-8

7.03

Probably not - relatively large seeds - ''The hairy pods are up to 15 cm long and contain 8 to 24 seeds (each seed is ca. 5 x 2.4 mm and weighs 0.09 mg).'

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

7.04

(1)'Spread primarily by seed floating away on water (Lonsdale 1992); observed to sink within 10days in Florida (Sutton and Langeland 1993).' (2)Water-dispersed seeds.

(1)http://plants.ifas.ufl.edu/invasivesbook2.pdf (2)http://www.hear.org/pier/species/mimosa_pigra.htm

7.05

(1)'Spread primarily by seed floating away on water (Lonsdale 1992); observed to sink within 10days in Florida (Sutton and Langeland 1993).' (2)Water-dispersed seeds. (3)The bristles also enable the pods to effectively float on water, enabling them to be easily spread downstream and onto floodplains adjacent to rivers.'

(1)http://plants.ifas.ufl.edu/invasivesbook2.pdf (2)http://www.hear.org/pier/species/mimosa_pigra.htm (3)http://216.239.57.104/search?q=cache:jTQQ2OQKEm4J:www.nrm.qld.gov.au
/factsheets/pdf/pest/PP25.pdf+Mimosa+pigra&hl=en&ie=UTF-8

7.06

(1)'Spread primarily by seed floating away on water (Lonsdale 1992); observed to sink within 10days in Florida (Sutton and Langeland 1993).' (2)Water-dispersed seeds.

(1)http://plants.ifas.ufl.edu/invasivesbook2.pdf (2)http://www.hear.org/pier/species/mimosa_pigra.htm

7.07

'The one seeded, bristled segments, of Mimosa pigra’s seed pods are easily spread by man, animals, and water. The segments stick to the fur of animals and pass unharmed through their digestive tract, they become attached to people’s clothing, and are transported in mud and on machinery.'

http://216.239.57.104/search?q=cache:jTQQ2OQKEm4J:www.nrm.qld.gov.au
/factsheets/pdf/pest/PP25.pdf+Mimosa+pigra&hl=en&ie=UTF-8

7.08

(1)Ungulates have little impact on M. pigra and some post dispersal seed predation occurs. (2) 'The one seeded, bristled segments, of Mimosa pigra’s seed pods are easily spread by man, animals, and water. The segments stick to the fur of animals and pass unharmed through their digestive tract, they become attached to people’s clothing, and are transported in mud and on machinery.'

(1)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm (2)http://216.239.57.104/search?q=cache:jTQQ2OQKEm4J:www.nrm.qld.gov.au
/factsheets/pdf/pest/PP25.pdf+Mimosa+pigra&hl=en&ie=UTF-8

8.01

(1)'Fruit a brown-bristly, segmented, flat pod to 8 cm (3 in) long and 1.4 cm (0.5 in) wide, with the 9-24 segments breaking free individually, each containing a seed; pods in clusters, or 'hands' of usually 7, at stem tips.' (2) Pods clustered, brown, densely bristly all over, breaking transversely into about 21 (14-26) partially dehiscent segments, each containing a seed, the pod sutures persisting as an empty frame. Seeds light brown to brown or olive green, oblong, light, dispersed by water and floating for an indefinite period. ... A prolific seed producer.' (3) 'The hairy pods are up to 15 cm long and contain 8 to 24 seeds (each seed is ca. 5 x 2.4 mm and weighs 0.09 mg).' (4) "can reach up to 12 000 seeds m-1 and seeds remain viable for more than two years"

(4) http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

8.02

(1)Seeds may remain dormant for many years. (2)The seeds can remain dormant in the ground for a number of years before germinating. (3) In northern Australia the soil seed banks can reach up to 12 000 seeds m-1 and seeds remain viable for more than two years.

(1)http://www.hear.org/pier/species/mimosa_pigra.htm (2)http://www.hort.agri.umn.edu/h5015/99papers/marko.htm (3)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm

8.03

'Chemical methods are currently the primary means of controlling mimosa populations. Over twenty-one herbicides (applications from aerial spraying, bark and stem injections and soil treatments) have been tested for their effectiveness (Lonsdale et al. 1995). Currently, 2,4,5-T, tebuthiuron (Graslan 20P®), fluroxypyr (Starane®), metsulfuron methyl (Brush-Off®), dicamba (Banvel 200®) and hexazinone (Velpar®) are the principal chemicals used to control mimosa (Lonsdale et al. 1995, Miller and Siriworakul 1992). The timing of application is critical in chemical treatment. Graslan is typically applied first and must be applied before the floodplain becomes wet but after the risk of fires is reduced. Stardane is then used to kill remaining scattered plants after Graslan application has defoliated the plants (Schultz and Barrow 1995). Fluroxypyr and metsulfuron methyl are recommended as aerially applied foliar spays. Mimosa needs to be actively growing in order to translocate tebuthiuron (a root absorbed residual

http://www.hort.agri.umn.edu/h5015/99papers/marko.htm

8.04

(1)Following natural fires the plants resprout freely. (2)Regrowth after severenig to the ground

(1)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp11.htm (2)http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP25.pdf

8.05

(1)The biological control program for Mimosa pigra commenced in 1979 with a collaborative program between CSIRO Entomology and Northern Territory Department of Primary Industry and Fisheries. The aim of the program is to better understand the ecology of mimosa and to implement biological control as part of a mimosa management plan. Surveys in South America, Mexico and Central America identified a number of potential species and to date ten insect species and two fungal pathogens have been released (see also Results to Date). While biological control on its own is unlikely to have a dramatic impact on the extensive infestation of mimosa currently found in the Top End, it will become an important management tool in the overall Integrated Weed Management strategy. An Integrated Weed Management (IWM) strategy aims to bring together a range of control techniques in order to achieve long-term control. Of the twelve biological control agents released in the field, five have reached sufficiently high densities

(1)http://www.ento.csiro.au/weeds/mimosa/ (2)http://www.hear.org/pier/species/mimosa_pigra.htm