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

Delairea odorata (Cape Ivy, german ivy, african ivy) Synonym: Senecio mikanioides

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

1

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

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

n

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

y

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

y

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

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

y

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

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

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

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

n

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:

14

Source

Notes

1.01

No evidence

1.02

(1)Naturalized in Hawaii and a serious pest in mamane forests on Mauna Kea. (2)California pest

(1)Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (20http://www.cnpssd.org/delairea.html

1.03

No evidence

2.01

Native to South Africa, widely cultivated as an ornamental.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.02

Native to South Africa, widely cultivated as an ornamental.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.03

Senecio grows in open, wet habitats, generally above 800 m. Dry forest, moist forest, coastal areas.

http://www.hear.org/pier3/deodo.htm

2.04

Native to South Africa, widely cultivated as an ornamental.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

2.05

Widley cultivated as an ornamental.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

3.01

(1)Naturalized in Hawaii and a serious pest in mamane forests on Mauna Kea. (2)California pest

(1)Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (20http://www.cnpssd.org/delairea.html

3.02

No evidence

3.03

No evidence

3.04

(1)'Significant weeds of conservation areas are inadequately documented at present, but include Delairea odorata, …' (2) 'This introduced plant is a widespread bushland weed in southern Victoria and elsewhere in Australia.' (3) Serious pest in mamane forests on Mauna Kea in Hawaii. (4) On New Zealand noxious weed list and banned from sale in that country. A weed in Australia and the US. (5)Cape ivy (Delairea odorata) formerly known as German ivy (Senecio mikanioides) is a highly invasive non-native weed of coastal California. It is rated List A-1 (most invasive) by the California Exotic Pest Plant Council (CalEPPC). (6)This noxious, light-loving vine grows rapidly into the emergent layers of forests where it festoons the vegetation. There are several infestations along the Saddle Road, e.g., Pulu Huluhulu, Hawai'i, and it is becoming established at upper elevations on Mauna Kea and Manuka.

(1) SCOTT-J-K {a}; DELFOSSE-E-S. 1992. SOUTHERN AFRICAN PLANTS NATURALIZED IN AUSTRALIA A REVIEW OF WEED STATUS AND BIOLOGICAL CONTROL POTENTIAL. Plant-Protection-Quarterly. 1992; 7 (2): 70-80. (2) FAGG-P-C. 1989. CONTROL OF DELAIREA-ODORATA CAPE IVY IN NATIVE FOREST WITH THE HERBICIDE CLOPYRALID. Plant-Protection-Quarterly. 1989; 4 (3): 107-110. (3) Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu. (4)http://www.hear.org/pier3/deodo.htm
(5)http://www.cnpssd.org/delairea.html (6)http://www.botany.hawaii.edu/faculty/cw_smith/sen_mik.htm

3.05

No evidence

4.01

No evidence

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

4.02

No evidence

4.03

No evidence

4.04

No information

4.05

(1) 'It is considered to be poisonous to infants and pets that consume it. Also, preliminary tests indicate that when it comes in contact with water, some toxic substance is released that kills fish and other aquatic organisms. ' (2)As many Senecio species contain alkaloids, which is very toxic to other living organisms (Heywood 1977), D. odorata also seems to have possibility of poisoning of aquatic environment. There is evidence that shows toxicity to aquatic organisms such as freshwater shrimp, and habitat of Coho salmon (Sigg 1999). (3)Poison to rabbits

(1)http://www.nal.usda.gov/ttic/tektran/data/000011/63/0000116353.html (2)http://bss.sfsu.edu/geog/bholzman/courses/fall99projects/capeivy.htm (3)http://www.allearssac.org/poison.html

4.06

Aecidium dubiosum was found to be associated with D. odorata. Did not find this fungus to be a recognized pest. No further informaiton regarding pests associated with this species.

4.07

'It is considered to be poisonous to infants and pets that consume it. Also, preliminary tests indicate that when it comes in contact with water, some toxic substance is released that kills fish and other aquatic organisms. '

http://www.nal.usda.gov/ttic/tektran/data/000011/63/0000116353.html

4.08

Unlikely, leaves semi-succulent texture

4.09

(1) 'This noxious, light-loving vine grows rapidly into the emergent layers …' (2) Will tolerate semi-shade

(1)http://www.hear.org/pier3/deodo.htm (2)http://www.igrin.co.nz/trisha/Breamhead.html

4.1

sandy loam soil [California]

http://www.caleppc.org/symposia/95symposium/bossard.html

4.11

(1)This noxious, light-loving vine grows rapidly into the emergent layers of forests where it festoons the vegetation. It can smother native vegetation and affect regeneration. (2)Cape-ivy forms impenetrable mats in both shade and sun, and climbs native shrubs and trees forming a dark canopy layer up to nine meters in height. Patch size ranges from a few square meters to several acres in size.

(1)http://www.hear.org/pier3/deodo.htm (2)http://groups.ucanr.org/ceppc/1997_CalEPPC_Symposium/Management_of_
Delairea_odorata_(Senecio_mikanioides)_at_Golden_Ga.htm?$=381

4.12

not thicket forming but smothering

5.01

A perennial vine - woody at the base.

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

5.02

5.03

5.04

storage of starch in the rhizomes

http://www.caleppc.org/symposia/95symposium/bossard.html

6.01

Propagates by seed.

http://www.hear.org/pier3/deodo.htm

6.02

Propagates by seed.

http://www.hear.org/pier3/deodo.htm

6.03

No information regarding hybridization

6.04

No information

6.05

Asteraceae (insect)

6.06

Cape-ivy expands vegetatively as a vine through the spread of stolons.

(1)http://www.hear.org/pier3/deodo.htm (2)http://groups.ucanr.org/ceppc/1997_CalEPPC_Symposium/Management_of_
Delairea_odorata_(Senecio_mikanioides)_at_Golden_Ga.htm?$=381

6.07

No information

7.01

Rooting of disposed plant part (yard waste, etc)

7.02

Probably yes as it is an attractive ornamental vine.

http://www.hear.org/pier3/deodo.htm

7.03

No information on seed size.

7.04

The seeds are wind-dispersed.

http://www.hear.org/pier3/deodo.htm

7.05

7.06

7.07

7.08

8.01

many smal seed heads [many sterile]

8.02

No information on seed longevity.

8.03

'Two exploratory trials were carried out in the Sherbrooke Forest to evaluate the selective herbicide Lontrel (active constituent 300 g L-1 clopyralid) for the control of Delairea odorata Lemaire (syn. Senecio mikanioides Otto ex Walp.) (Cape Ivy). This introduced plant is a widespread bushland weed in southern Victoria and elsewhere in Australia. Within 11 weeks of treatment, good control was obtained with Lontrel applied using either hand-held rope-wick or controlled-droplet applicators. Summer and winter applications resulted in similar levels of control. However, in the absence of follow-up treatment, D. odorata had re-colonized the plots to 50-70% of the original extent within 12 months. For long-term control, follow-up chemical or manual/mechanical treatment within 6-9 months of the initial treatment is clearly essential. ...' [requires frequent followup]

8.04

Tiny portions of stem can survive for long periods before resprouting.

http://www.nps.gov/redw/c-ivy.htm

8.05

Don’t know.