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

Carissa grandiflora; Natal plum

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

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

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

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

y

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

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

2

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

y

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

n

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

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:

-1

Source

Notes

1.01

no evidence

1.02

no evidence

1.03

no evidence

2.01

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

List of countries with natural populations
South Africa (natal), Mozambique-- more Mediteranean than sub-tropical

2.02

2.03

1)Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref. 2)http://www.floridata.com/ref/C/cari_mac.cfm

2)USDA zones 9-11

2.04

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

List of countries with natural populations
Africa:Mozambique; South Africa

2.05

(1)Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref. (2)Ranbir Singh; Chopra, D. P.; Gupta, A. K. (1982) Some carissas for western Rajasthan. Indian Horticulture, 1982, Vol.27, No.3, pp.10-11 (3) Lev-Yadun, S.; Aloni, R. (1990) Polar patterns of periderm ontogeny, their relationship to leaves and buds, and the control of cork formation. IAWA Bulletin, 1990, Vol.11, No.3, pp.289-300, 65 ref.

(1)California (2)India (3) Israel

3.01

no evidence

3.02

no evidence

3.03

no evidence

3.04

no evidence

3.05

no evidence

4.01

Cohen, L.; Arzee, T.(1980) Twofold pathways of apical determination in the thorn system of Carissa grandiflora. Botanical Gazette, 1980, Vol.141, No.3, pp.258-262, 11 ref.

AB: "Individual branches of the sympodial shoot system ususally bore 2-3 pairs of decussate leathery ovate foliage leaves and a pair of inconspicuous opposite ovate scale leaves from whose axils the branched thorny shoots grew. "

4.02

no evidence

4.03

free living shrub

4.04

Habitat and diet of bushbuck Tragelaphus scriptus in the Woody Cape Nature Reserve: Observations... By: MacLeod, S.B.; Kerly, G.I.H.; South African Journal of Wildlife Research, Mar96, Vol. 26 Issue 1, p19

Browsed by Bushbuck (deer) in S. Africa

4.05

no evidence

4.06

(1) Mohammed, M. S.; Al-Namlah, S. A.; Vaughan, N. A. Q. (1987) Leaf blight of Carissa grandiflora DC. Indian Journal of Botany, 1987, Vol.10, No.2, pp.149-151, 6 ref.
(2) Marlatt, R. B.; Ridings, W. H. (1976) Sphaeropsis disease of Carissa grandiflora. Plant Disease Reporter, 1976, Vol.60, No.10, pp.842-843, 1 ref.
(3) McCoy, R. E. (1972) Carissa dieback: etiology suggests control. Proceedings of the Florida State Horticultural Society, 1972, Vol.85, pp.363-364

(1) AB: A previously undescribed leaf blight occurred on this ground cover plant at the airport in Riyadh during Oct.-Nov. 1985, caused by the new species, Cercospora saudiaii [C. saudii] which is described. The disease occurred again in 1986 and devastated plants in the nursery.
(2) AB: S. tumefaciens causes cankers and galls on C. grandiflora, an ornamental shrub grown in subtropical areas of Fla. Pathogenicity was confirmed in inoculation tests.
(3) AB: Both Rhizoctonia solani [RPP 52, 151] and Phytophthora sp. were consistently isolated from diseased C. grandiflora. Benomyl was ineffective against P. sp. but controlled R. solani, whereas terrazole controlled only P. sp.

4.07

http://www.floridata.com/ref/C/cari_mac.cfm

leaves toxic (but not eaten by humans). Fruits not toxic

4.08

Firescaping. By: Bolton, J.; Horticulture, Oct91, Vol. 69 Issue 8, p54,

Recommended as a fire barrier

4.09

1)Michigan State University Extension
Home Horticulture - 01700173 01/01/96
Carissa grandiflora - Natal Plum <http://www.msue.msu.edu/msue/imp/mod03/01700173.html> 2)http://www.floridata.com/ref/C/cari_mac.cfm 3)http://home.global.co.za/~dcs/carmac/carmac.html

"Best flowering occurs in high light or full sun. As a foliage plant, moderate light intensity will suffice. " 2) Tolerates partial shade 3)Full sun - Semi shade

4.1

(1) Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref. (2) Bernstein, L.; Francois, L. E.; Clark, R. A. (1972) Salt tolerance of ornamental shrubs and ground covers. Journal of the American Society for Horticultural Science, 1972, Vol.97, No.4, pp.550-556, 17 ref.

(1) page 77: Soil requirements are not stringent as the bush grow well on a wide variety of soil from beach sand to heavy clay. (2) AB: The salt tolerance of 25 shrub and ground-cover species was determined in soil plots artificially salinized with NaCl + CaCl2. Chloride and Na injury was also observed in sand cultures of the same species with 4 different salt treatments. Tolerant species such as Bougainvillea spectabilis, Natal plum (Carissa grandiflora) and rosemary were affected little, if at all, by soil salinities of 8 mmho/cm (electrical conductivity of the saturation extract: ECe), whereas sensitive species such as Trachelospermum jasminoides, guava, holly and rose were severely damaged or killed at ECe levels of 4 mmho/cm.

4.11

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

shrub

4.12

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

Impenetrable, thorny hedge

5.01

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

terrestrial shrub to samll tree

5.02

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

shrub to samll tree

5.03

no evidence

5.04

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

shrub to small tree

6.01

no evidence

6.02

http://www.floridata.com/ref/C/cari_mac.cfm

The species may be grown from seed

6.03

no evidence

6.04

1) Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref. 2)http://newcrop.hort.purdue.edu/newcrop/morton/carissa.html

page 80: "The factor for self-sterility in Carissa would apear to be dominant so careful A FEW PLANTS MAY BE ARE SELF_FERTILE: 1)selection &screen should be done to find only self-fertile types "; page 75 " a variety is self-fertile" 2)It has been found that unproductive plants, apparently self-infertile, will bear fruits after cross-pollination by hand.

6.05

http://newcrop.hort.purdue.edu/newcrop/morton/carissa.html

carissa is pollinated by small beetles and hawk-moths and other night-flying insects

6.06

no evidence

6.07

Seedlings may begin to produce fruit in 2 years;

Seedlings may begin to produce fruit in 2 years;

7.01

no evidence

7.02

Thompson, P. H. (1976) The carissa in California. California Rare Fruit Growers Yearbook, 1976, Vol.8, pp.73-81, 9 ref.

grow for fruit and landscaping

7.03

no evidence

7.04

red juicy fruit

7.05

no evidence

7.06

red juicy fruit

7.07

no evidence

7.08

Seed dispersal by vervet monkeys in rehabilitating coastal dune forests at Richards Bay. By: Foord, S.H.; van Aarde, R.J.; South African Journal of Wildlife Research, Sep94, Vol. 24 Issue 3, p56

red juicy fruit, survives digestive tract of monkeys

8.01

Ranbir Singh; Chopra, D. P.; Gupta, A. K. (1982) Some carissas for western Rajasthan. Indian Horticulture, 1982, Vol.27, No.3, pp.10-11

page 11 "average 15 seeds/fruit; average weight 7.8 gram/fruiy; a 7-8 year old plant (100-160 cm tall) produces 500-600 gram of fruiy/year." [ca. 1058 seeds/plant per year, I think the plant will occupied more than 1.058 square meter, which means less than 1000 seeds/square meter]

8.02

no evidence

8.03

Neel, P. L. (1976) Comparisons of phytotoxicity between soil-applied dicamba and two rates of an experimental dicamba analogue on twenty-three containerized species of environmental plants. Proceedings of the Florida State Horticultural Society, 1976, Vol.89, pp.341-343, 3 ref.

AB: "Acalypha wilkesiana, Asparagus densiflorus cv. Sprengeri, Brassaia [Schefflera] actinophylla, Carissa grandiflora, Coccoloba uvifera, Ficus benjamina, Ixora coccinea, Jasminum volubile, Ligustrum japonicum, Murraya paniculata and Viburnum suspensum were especially sensitive to the analogue at the lower rate. "

8.04

http://www.floridata.com/ref/C/cari_mac.cfm

responds well to close pruning

8.05