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

Carpobrotus edulis (Mesembryanthemum edule); hottentot fig, ice plant, pigface.

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

1

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

n

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

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

y

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

y

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

n

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

y

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

y

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

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

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

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

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:

9.5

Source

Notes

1.01

no evidence

1.02

(1) Suehs, C. M.; Médail, F.; Affre, L. (2001) Ecological and genetic features of the invasion by the alien Carpobrotus plants in Mediterranean island habitats. ED: Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. Plant invasions: species ecology and ecosystem management, 2001, pp.145-157, many ref.
(2) D'Antonio, C. M. (1993) Mechanisms controlling invasion of coastal plant communities by the alien succulent Carpobrotus edulis . Ecology, 1993, Vol.74, No.1, pp.83-95, 59 ref.
(3) Collins, L.; Scott, J. K. (1982) Interaction of ants, predators and the scale insect, Pulvinariella mesembryanthemi, on Carpobrotus edulis, an exotic plant naturalized in Western Australia. Australian Entomological Magazine, 1982, Vol.8, No.5, pp.73-78, 12 ref.
(4) Guerreiro, A. R. (1976) Evaluation trials for herbicides to control hottentot-fig (Carpobrotus edulis (L.) N.E.Br.). [FT: Ensaios de comportamento de herbicidas contra os choroes (Carpobrotus edulis (L.) N.E. Br.).] Proceedings II Simposio Nacional de He

introduced and naturalized repeatively (1) France, (2) California, (3) Australia, (4) Portugal, (5) Spain

1.03

Maddams, W. F. (1989) Flower colour variation of Carpobrotus edulis. British Cactus and Succulent Journal, 1989, Vol.7, No.1, pp.16-17, 4 ref.

AB: Observations on natural populations in the Isles of Scilly showed that 3 types of flower were present. The major type was bright yellow, with no change in colour as the flower aged. The second was initially yellow but assumed a flesh-coloured or clear pink tint after 2-3 days. The third, and least frequent, was pink-magenta with no colour change with age. [known to be a weed, and flower variation observed]

2.01

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.ceh.ac.uk/EPIDEMIE/EPIDEMIE%20test/
Species%20descriptions/Accounts/Carpobrotus%20edulis.htm

(1)Native Habitat: South Africa [Cape Region} (2)Widely naturalised on rocks, cliffs and sands by the sea in both California and the Mediterranean Basin. [NOT tropical or sub-tropical]

2.02

2.03

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)
(2) Mitchley, J. (1988) Weed control and vegetation management of British sea-cliff vegetation. Aspects of Applied Biology, 1988, No.16, pp.403-406, 10 ref.

(1) Hardiness Range 8B to 11 (2) able to invade cliff vegetation in the UK [restricted to coastal environment]

2.04

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

Native Habitat: South Africa; also naturalized in regions of Meditarrenean climate

2.05

(1) Suehs, C. M.; Médail, F.; Affre, L. (2001) Ecological and genetic features of the invasion by the alien Carpobrotus plants in Mediterranean island habitats. ED: Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. Plant invasions: species ecology and ecosystem management, 2001, pp.145-157, many ref.
(2) D'Antonio, C. M. (1993) Mechanisms controlling invasion of coastal plant communities by the alien succulent Carpobrotus edulis . Ecology, 1993, Vol.74, No.1, pp.83-95, 59 ref.
(3) Collins, L.; Scott, J. K. (1982) Interaction of ants, predators and the scale insect, Pulvinariella mesembryanthemi, on Carpobrotus edulis, an exotic plant naturalized in Western Australia. Australian Entomological Magazine, 1982, Vol.8, No.5, pp.73-78, 12 ref.
(4) Guerreiro, A. R. (1976) Evaluation trials for herbicides to control hottentot-fig (Carpobrotus edulis (L.) N.E.Br.). [FT: Ensaios de comportamento de herbicidas contra os choroes (Carpobrotus edulis (L.) N.E. Br.).] Proceedings II Simposio Nacional de He

introduced and naturalized repeatively (1) France, (2) California, (3) Australia, (4) Portugal, (5) Spain

3.01

(1) Suehs, C. M.; Médail, F.; Affre, L. (2002) Ecological and genetic features of the invasion by the alien Carpobrotus plants in Mediterranean island habitats. ED: Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. Plant invasions: species ecology pp.125-134, 18 ref.
(5) Results of the recuperation of biodiversity in the Racó de l'Olla (l'Albufera de València) aftHļoJ!���HĤve application of caculia and a low risk herbicide. [FT: Resultados en la recuperación de la biodiversidad en el Racó de l'Olla (l'Albufera

introduced and naturalized repeatively (1) France, (2) California, (3) Australia, (4) Portugal, (6) Spain

3.02

no evidence

3.03

no evidence

3.04

(1) Suehs, C. M.; Médail, F.; Affre, L. (2001) Ecological and genetic features of the invasion by the alien Carpobrotus plants in Mediterranean island habitats. ED: Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. Plant invasions: species ecology and ecosystem management, 2001, pp.145-157, many ref.
(2) CalEPPC. California Exotic Pest Plant Council. 1999. Exotic pest plant list (http://www.caleppc.org/info/plantlist.html, 19 October 1999). California Exotic Pest Plant Council. (3)http://www.serg.sdsu.edu/SERG/restorationproj/chaparraland
/point_loma/fleetcombat/sloperestoration.htm (4)

(1) AB: "Carpobrotus acinaciformis and C. edulis are trailing, mat-forming succulents that have now invaded diverse coastal continental and island habitats in Mediterranean France. The present study is focused on two Carpobrotus patches on the island of Bagaud (Hyères archipelago, Provence, France) where the two taxa have proven to be highly invasive within natural plant communities [date not given].
(2) On California's invasive plant list (3)There is evidence that iceplant also competes indirectly with native species. It has been reported that iceplant can lower soil pH and also affect the root morphology of some native shrubs (D'Antonio, 1990a; D'Antonio and Mahall, 1991). It is also possible, because iceplant does not seem to be palatable to most native herbivores, that its presence could increase browsing pressure on native flora and influence the species composition of herbivorous fauna. (3) Invasion by the alien succulent, C. edulis , has become a common occurrence after fire in maritime chaparral in

3.05

no evidence

4.01

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

no description of these traits

4.02

(1)http://www.ceh.ac.uk/EPIDEMIE/EPIDEMIE%20test/
Species%20descriptions/Accounts/Carpobrotus%20edulis.htm (2)http://userwww.sfsu.edu/~conser/

(1)Accumulates salts that decrease nutrient availability or dramatically alter soil pH. (2)it has been shown to reduce soil pH, acidifying the soil, which impacts nitrogen availability to other species (D'Antonio and Haubensak 1998).

4.03

no evidence

4.04

http://www.gencat.es/mediamb/bioplatform/bs1contr_23.htm

seedlings are subjected to herbivory 'Although the seed dispersal of Carpobrotus by animals have been proved (D’Antonio, 1990). It seems that in the particular case of Favàritx, traditional grazing has operated as a restriction to the expansion of this plant. In fact, in other parts of the island with similar conditions, where grazing still exists and Carpobrotus is cultivated it doesn’t expand, it remains only where the cattle don’t graze (i.e. inside the fenced off area of a lighthouse). '

4.05

D'Antonio, C. M.; Odion, D. C.; Tyler, C. M. (1993) Invasion of maritime chaparral by introduced succulent Carpobrotus edulis . Oecologia, 1993, Vol.95, No.1, pp.14-21, 44 ref.

AB: "In a field experiment involving the use of herbivore exclosures, it was found that herbivory was an important source of mortality for seedlings in both burned and unburned chaparral. "

4.06

no evidence

4.07

no evidence

4.08

unlikely, a succulent plant

4.09

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

Exposure: Full sun

4.1

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.gardenbed.com/C/921.cfm

(1)Soil Condition Loamy, sandy, acidic, neutral, drought tolerant (2)well-drained sandy soil

4.11

http://userwww.sfsu.edu/~conser/

forming dense mats that spread radially (Albert 1995). Individuals grow rapidly with individual branches growing more than one meter per year and rooting occuring at nodes that come into contact with the soil surface as the plant grows (D’Antonio 1990). Carpobrotus edulis has a dense network of fibrous roots that are concentrated in the upper 50 cm of the soil (D’Antonio and Mahall 1991). Branches often grow over one another, resulting in a thick mat of live and dead plant material up to 40 cm in depth (D’Antonio 1990)

4.12

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-8.

low, spreading groundcover

5.01

terrestrial

5.02

Aizoaceae (Mesembryanthemaceae)

5.03

Aizoaceae (Mesembryanthemaceae)

5.04

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-8.

underground storage organ not known

6.01

no evidence

6.02

Vilà, M.; D'Antonio, C. M. (1998) Fruit choice and seed dispersal of invasive vs. noninvasive Carpobrotus (Aizoaceae) in coastal California. Ecology, 1998, Vol.79, No.3, pp.1053-1060, 35 ref.

AB: "Germination of seeds from C. edulis and hybrids was enhanced after gut passage"

6.03

Weber, E.; D'Antonio, C. M. (1999) Phenotypic plasticity in hybridizing Carpobrotus spp. (Aizoaceae) from coastal California and its role in plant invasion. Canadian Journal of Botany, 1999, Vol.77, No.10, pp.1411-1418

AB: "Carpobrotus edulis , an exotic perennial that invades the coastal habitats of California, hybridizes with the presumed native Carpobrotus chilensis . "

6.04

Vilà, M.; Weber, E.; D'Antonio, C. M. (1998) Flowering and mating system in hybridizing Carpobrotus (Aizoaceae) in coastal California. Canadian Journal of Botany, 1998, Vol.76, No.7, pp.1165-1169, 34 ref.

AB: "Emasculation and bagging experiments suggest that C. edulis and hybrid morphotypes have facultative agamospermia"

6.05

Vilà, M.; Weber, E.; D'Antonio, C. M. (1998) Flowering and mating system in hybridizing Carpobrotus (Aizoaceae) in coastal California. Canadian Journal of Botany, 1998, Vol.76, No.7, pp.1165-1169, 34 ref.

AB: "visited by the same Thysanoptera and Coleoptera taxa" ; "Emasculation and bagging experiments suggest that C. edulis and hybrid morphotypes have facultative agamospermia"

6.06

Suehs, C. M.; Médail, F.; Affre, L. (2001) Ecological and genetic features of the invasion by the alien Carpobrotus plants in Mediterranean island habitats. ED: Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. Plant invasions: species ecology and ecosystem management, 2001, pp.145-157, many ref.

AB: "C. edulis shows a mixed sexual mating system as a reproductive alternative to a weaker capacity for vegetative growth."

6.07

don't know

7.01

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

"A common road-side ground cover in California" [Garden waste]

7.02

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

use as a oramental groundcover

7.03

no evidence

7.04

Vilà, M.; D'Antonio, C. M. (1998) Fruit choice and seed dispersal of invasive vs. noninvasive Carpobrotus (Aizoaceae) in coastal California. Ecology, 1998, Vol.79, No.3, pp.1053-1060, 35 ref.

AB: "Scats from black-tailed jackrabbit (Lepus californicus ) and mule deer (Odocoileus hemionus ), the most common frugivores in experimental sites, contained more seeds from C. edulis and hybrid morphotypes than from C. chilensis , and more than would be expected based on relative fruit abundance. Germination of seeds from C. edulis and hybrids was enhanced after gut passage" [with fleshy fruit]

7.05

no evidence

7.06

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

"inconspicuous fruit"

7.07

no evidence

7.08

Vilà, M.; D'Antonio, C. M. (1998) Fruit choice and seed dispersal of invasive vs. noninvasive Carpobrotus (Aizoaceae) in coastal California. Ecology, 1998, Vol.79, No.3, pp.1053-1060, 35 ref.

AB: "Scats from black-tailed jackrabbit (Lepus californicus ) and mule deer (Odocoileus hemionus ), the most common frugivores in experimental sites, contained more seeds from C. edulis and hybrid morphotypes than from C. chilensis , and more than would be expected based on relative fruit abundance. Germination of seeds from C. edulis and hybrids was enhanced after gut passage"

8.01

Vilà, M.; D'Antonio, C. M. (1998) Fruit choice and seed dispersal of invasive vs. noninvasive Carpobrotus (Aizoaceae) in coastal California. Ecology, 1998, Vol.79, No.3, pp.1053-1060, 35 ref.

p.1055 "clone size average 36.03 square meter"; p.1056 "C. edulis bore on average 497 fruits/clone"' Table 1 No. seeds/fruit 1573.
[1573x497/36.03 = 21698 seeds per square meter]

8.02

D'Antonio, C. M.; Odion, D. C.; Tyler, C. M. (1993) Invasion of maritime chaparral by introduced succulent Carpobrotus edulis . Oecologia, 1993, Vol.95, No.1, pp.14-21, 44 ref.

"C. edulis seeds were abundant in deer scat and in the soil before burning. "; "seeds were present in soil bank before burning"; "C edulis is an obligate animal dispersed plant and fruit that remain on the plant become very hard, fall beneath the plant and take up to 3 year to decompose. Seeds don't germinate while in the fruit."

8.03

Guerreiro, A. R. (1976) Evaluation trials for herbicides to control hottentot-fig (Carpobrotus edulis (L.) N.E.Br.). [FT: Ensaios de comportamento de herbicidas contra os choroes (Carpobrotus edulis (L.) N.E. Br.).] Proceedings II Simposio Nacional de Herbologia, Oeiras, 1976., 1977, No.Volume III, pp.125-134, 18 ref.

AB: "Of a large number of herbicides and mixtures screened, glyphosate at 5.4 kg/ha gave the most rapid and complete control; with 3.6 kg/ha control was still excellent if less swift. Paraquat + simazine at 1.6 + 3 kg/ha gave satisfactory and benzoylprop-ethyl at 2 kg/ha gave adequate control. "

8.04

(1)http://www.gardenbed.com/C/921.cfm (2)http://www.northcoast.com/~cnps/iwhc/iwhca1.htm

(1)Cuttings at any time during the growing season. Allow the cutting to dry in the sun for a day or two then pot up in a very sandy mix. Very easy [regrowth from fragments] (2)Iceplant regrows from underground stems so you�ll need to repeat your treatment for several seasons.

8.05

no evidence