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

Desmanthus virgatus (Mimosa virgata; slender mimosa, false tamarind, wild tantan, bundleflower)

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

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

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

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

y

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

1

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

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

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

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:

12

Notes

Source

1.01

No evidence

1.02

(1)A copious seeder and colonizer of ruderal sites, D. virgatus is locally naturalized in several areas and has the potential to become weedy. (2)Naturalized in Hawaii and Florida and in many other tropical countries.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://216.239.57.104/search?q=cache:93CCArNeYnIJ:www.fs.fed.us
/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

1.03

Three cultivars have been released, of different species and flowering times.
D. virgatus cv. Marc is short (30-60 cm) and early flowering; D.leptophyllus cv.Bayamo is tall (95-135 cm) and flowers in the mid-season; D. pubescens cv. Uman is middle height (40-100 cm) and late-flowering. Seed merchants will mix seed of these cultivars to suit local conditions. [No evidence that these cultivars are weedy.]

http://www.tropicalgrasslands.asn.au/pastures/desmanthus.htm

2.01

(1)It is a variable species across its very extensive natural distribution in the Americas. D. virgatus is adaptable to a wide range of tropical and subtropical climates and has been introduced worldwide. (2)Native range: Caribbean and tropical South America.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://www.hear.org/pier/devir.htm

2.02

It is a variable species across its very extensive natural distribution in the Americas. D. virgatus is adaptable to a wide range of tropical and subtropical climates and has been introduced worldwide.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

2.03

(1)Approximate limits north to south: 31°N to 32°S Altitude range: 0 - 1000 m (2)Near sea level to 300 m [lowland plant] (3)tropical wet & dry (Aw), desert or arid (Bw), steppe or semiarid (Bs), subtropical humid (Cf), subtropical dry winter (Cw)

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://216.239.57.104/search?q=cache:93CCArNeYnIJ
:www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8 (3)http://ecocrop.fao.org/

2.04

It is a variable species across its very extensive natural distribution in the Americas. D. virgatus is adaptable to a wide range of tropical and subtropical climates and has been introduced worldwide.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

2.05

It is a variable species across its very extensive natural distribution in the Americas. D. virgatus is adaptable to a wide range of tropical and subtropical climates and has been introduced worldwide.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

3.01

(1)A copious seeder and colonizer of ruderal sites, D. virgatus is locally naturalized in several areas and has the potential to become weedy. (2)Naturalized in Hawaii and Florida and in many other tropical countries.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://216.239.57.104/search?q=cache:93CCArNeYnIJ
:www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

3.02

(1)Listed as a common garden weed in Australia. (2)A copious seeder and colonizer of ruderal sites, D. virgatus is locally naturalized in several areas and has the potential to become weedy. (3)Disappears when overtopped by trees. [disturbance weed]

(1)http://216.239.57.104/search?q=cache:LbwtqvZ82ZAJ:
www.nt.gov.au/dbird/dpif/pubcat/agnotes/Home%2520%26%2520
Flowers/495.pdf+Desmanthus+virgatus+herbicides&hl=en&ie=
UTF-8 (2)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (3)http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

3.03

(1)The species can become a serious weed in sugar cane fields. (2)Because of its vigor, the plant can become a troublesome weed in cultivated fields

(1)http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.
pdf+Desmanthus+virgatus&hl=en&ie=UTF-8 (2)http://ecocrop.fao.org/

3.04

No evidence

3.05

AB: The clay soils of the Mississippi River alluvial plain are amenable to no presowing tillage (stale) seedbed sowing, a practice used to achieve earlier sowing of soyabeans on these soils. Comparisons of sowing in stale and conventional seedbeds for 2 yr at 2 locations demonstrated that earlier sowing was achieved with acceptable weed control. Absence of preplant tillage led to the presence of early germinating summer annuals including Conyza canadensis, Polygonum lapathifolium and Aster exilis. Some perennials increased in the stale seedbed areas especially where pre-em. herbicides were not used including Rumex crispus, Desmanthus illinoensis, Paspalum distichum, Brunnichia cirrhosa, Campsis radicans and Solanum carolinense. The most abundant weed in all plots was Sida spinosa and was especially prominent in stale seedbed areas where no pre-em. weed control was used. It was also a problem in conventional tillage situations when not controlled soon after emergence. The success of stale seedbeds for sowing s

4.01

No evidence of such structures.

http://www.hear.org/pier/devir.htm

4.02

Not allelopathic.

http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3

4.03

No evidence

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

4.04

(1)D. virgatus is a small, nitrogen-fixing shrub 1.5-3 m tall used mainly for its high-quality forage. … It is tolerant of drought, moderate frost, and clay soils, and will persist under intensive grazing. (2)Palatable Browse Animal - High, Palatable Graze Animal - High

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3

4.05

(1)Toxicity- None. (2)'The forage is nontoxic and palatable to cattle and other ruminants. It is a favorite of white-tailed deer in southern Texas.'

(1)http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3 (2)http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

4.06

AB: Field samples and seedlings of 51 leguminous forage species were tested for alfalfa mosaic alfamovirus (AMV) in routine monitoring of seed multiplication fields of the International Livestock Research Institute (ILRI), Ethiopia. The virus was detected in 24 species and a solanaceous weed Solanum nigrum. Of these, the following 17 species are reported for the first time as hosts of the virus: Aeschynomene falcata, Centrosema pascuorum, Chamaecrista rotundifolia, Desmanthus virgatus, Desmodium intortum, Leucaena leucocephala, Macroptilium atropurpureum, Macroptilium lathyroides, Macrotyloma axillare, Medicago truncatula, Neonotonia wightii, Sesbania sesban, Stylosanthes scabra, Trifolium calocephala, T. steudneri, T. tembense and Vigna parkeri. The solanaceous weed S. nigrum was suspected to play a role in the virus epidemiology. The level of seed infection varied from 0.00% to about 13.00%. Infectivity studies on 5 isolates of the virus revealed heterogeneity in prevalent AMV isolates. Two major strains we

4.07

Toxicity - None.

http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3

4.08

Not fire resistant. Low fire tolerance. [depends upon whether dense stands have formed]

http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3

4.09

Wild-tantan is intolerant of shade. It tolerates severe competition from grass and herbs but disappears when overtopped by trees.

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

4.1

(1)Soil texture: light; medium; heavy
Soil drainage: impeded
Soil reaction: acid; neutral; alkaline
Special soil tolerances: infertile (2)Adapted to coarse, medium and fine textured soils. pH range 5 to 8. (3)Wild-tantan grows well in deep, well- to moderately well-drained silts, clays, loams, and sands with pH’s from about 5 to about 8... '

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3 (3)http://216.239.57.104/search?q=cache:93CCArNeYnIJ
:www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

4.11

Shrub. Not a vine.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://www.hear.org/pier/devir.htm

4.12

The species is usually more or less evenly dispersed in stands of grass and herbs, often at 1 or 2 per square meter.

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

5.01

Terrestrial

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

5.02

D. virgatus is a small, nitrogen-fixing shrub 1.5-3 m tall used mainly for its high-quality forage.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

5.03

D. virgatus is a small, nitrogen-fixing shrub 1.5-3 m tall used mainly for its high-quality forage.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

5.04

D. virgatus is a small, nitrogen-fixing shrub 1.5-3 m tall used mainly for its high-quality forage.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

6.01

'Seeds collected in Puerto Rico weighed an average of 0.0041 + 0.0005 g/seed or 244,000 seeds/kg.'

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

6.02

(1)Stand establishment using natural regeneration; direct sowing (2)Propagation: Seed.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://www.hear.org/pier/devir.htm

6.03

no evidence

6.04

no evidence

6.05

Mimosa type legume flower (insect syndrome)

http://www.hear.org/pier/images/devirp9.jpg

6.06

Vegetative spread rate - slow. Does not propagate through tubers, corm, bulb or cuttings. Propagates by seed.

http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3

6.07

(1)sometimes annual small shrub or herb

http://ecocrop.fao.org/

7.01

pods glabrous [no evidence that the propagules have any means of attachment.]

http://www.hear.org/pier/species/desmanthus_virgatus.htm

7.02

Descriptors: agroforestry; soil improvement; soil conservation; erosion control products
2. Non-wood Descriptors: fodder; mulches; green manures

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

7.03

relatively large seeds. (1) 'Seeds shiny dark to reddish brown; ovoid, about 3 mm long.' (2)Seeds 13-22 per pod, 2.4-3.2 mm long, 1.9-2.4 mm wide, obliquely inserted, ovate and flattened or rhomboidal and 4-angled, black or red-brown; pleurogram 0.7-1.0 mm wide, 0.7-1.5 mm deep, deeply U-shaped, symmetrical.”

http://www.hear.org/pier/devirp.htm

7.04

Relatively large legume seeds. No evidence that the seeds have any adaptations for wind dispersal. (see photo). 'Fruiting peduncles 2.4-5.6 cm long bearing 1-7 pods; legumes dehiscent along both sutures, the sutural ridges curling back over the valves causing the inner surface of the pods to be slightly convex; ...'

http://www.hear.org/pier/devirp.htm

7.05

'In nature, scarification occurs by weathering of the seed coat in the soil or while passing through an herbivore.' … 'The seeds are dispersed by ruminant animals. '

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

7.06

'In nature, scarification occurs by weathering of the seed coat in the soil or while passing through an herbivore.' … 'The seeds are dispersed by ruminant animals. '

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

7.07

'In nature, scarification occurs by weathering of the seed coat in the soil or while passing through an herbivore.' … 'The seeds are dispersed by ruminant animals. '

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

7.08

'In nature, scarification occurs by weathering of the seed coat in the soil or while passing through an herbivore.' … 'The seeds are dispersed by ruminant animals. '

http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

8.01

(1) 'Seeds shiny dark to reddish brown; ovoid, about 3 mm long.' (2)Seeds 13-22 per pod, 2.4-3.2 mm long, 1.9-2.4 mm wide, obliquely inserted, ovate and flattened or rhomboidal and 4-angled, black or red-brown; pleurogram 0.7-1.0 mm wide, 0.7-1.5 mm deep, deeply U-shaped, symmetrical.”
(3) Seeds collected in Puerto Rico weighed an average of 0.0041 + 0.0005 g/seed or 244,000seeds/kg.

(3) http://www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%20virgatus.pdf

8.02

Placed to germinate on moist filter paper, only 28 percent germinated in 1 year. The remaining seeds were scarified (by nicking) and 100 percent germinated starting in 2 da

http://www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%20virgatus.pdf

8.03

No evidence that the species is being controlled for.

8.04

(1)regenerate rapidly; suited for coppicing; suited for pollarding (2)Coppice potential - No. Resprout ability - Yes. (3)It withstands heavy grazing pressure and recovers well from fire.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://plants.usda.gov/cgi_bin/plant_attribute.cgi?symbol=DEVI3 (3)http://216.239.57.104/search?q=cache:93CCArNeYnIJ:
www.fs.fed.us/global/iitf/pdf/shrubs/Desmanthus%2520virgatus.pdf+Desmanthus+virgatus&hl=en&ie=UTF-8

8.05