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

Gazania rigens var. leucolaena; trailing gazania, treasure flower

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

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

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

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

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

y

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

y

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

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

n

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

8.05

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

y=-1, n=1

Total score:

9

Notes

Source

1.01

no evidence

1.02

http://www.environment.sa.gov.au/coasts/coastcare/plants.pdf

invade dunes/cliffs/wetlands in Australia

1.03

Several varieties and cultivars

(1)http://www.desert-tropicals.com/Plants/Asteraceae/Gazania.html (2)http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/annuals/gazania_rigens.html

2.01

USDA, ARS, National Genetic Resources Program.
Germplasm Resources Information Network - (GRIN) [Online Database].
National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Gazania+rigens (17 November 2003)

Native:
AFRICA
South Tropical Africa: Mozambique
Southern Africa: South Africa - Cape Province [e.], Natal, Transvaal

2.02

2.03

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://mtsgardening.com/Feb%202002.htm

(1) Hardiness Range 9A to 10A (2)drought tolerant [spreading on coastal dunes]

2.04

USDA, ARS, National Genetic Resources Program.
Germplasm Resources Information Network - (GRIN) [Online Database].
National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Gazania+rigens (17 November 2003)

Native:
AFRICA
South Tropical Africa: Mozambique
Southern Africa: South Africa - Cape Province [e.], Natal, Transvaal

2.05

(1) Australia, NuFlora International Pty Ltd (2002) 'Gavol'. Application no. 2002/122. Plant Varieties Journal, 2002, Vol.15, No.4, pp.32-33
(2) Erwin, J. E.; Warner, R. M. (2002) Determination of photoperiodic response group and effect of supplemental irradiance on flowering of several bedding plant species. ED: Dorais, M. Acta Horticulturae, 2002, No.580, pp.95-99, 3 ref.
(3) Molfino, M. (2001) Thirty new hybrids from Fleuroselect. [FT: Da fleuroselect trenta nuovi ibridi.] Colture Protette, 2001, Vol.30, No.8, pp.63-66, 68
(4) Pittenger, D. R.; Shaw, D. A.; Hodel, D. R.; Holt, D. B. (2001) Responses of landscape groundcovers to minimum irrigation. Journal of Environmental Horticulture, 2001, Vol.19, No.2, pp.78-84, 16 ref.
(5) Rao, V. G.; Yadav, B. R. D. (1995) Some hitherto undescribed fungal diseases on ornamental plants. Journal of the Annamalai University. Part B, Sciences, 1995, Vol.37, pp.79-86, 5 ref.

(1) Australia, (2) Minnesota, USA , (3) Europe , (4) California, USA, (5) India

3.01

http://www.environment.sa.gov.au/coasts/coastcare/plants.pdf

invade dunes/cliffs/wetlands in Australia

3.02

no evidence

3.03

no evidence

3.04

(1) http://www.environment.sa.gov.au/coasts/coastcare/plants.pdf (2) http://www.n2.net/cschneid/Newsletters/2002/May2002/InvasiveExoticsManagerRep.pdf (3)Randall, R. 2001. Garden thugs, a national list of invasive and potentially invasive garden plants. Plant Protection Quarterly 16:138-171.

(1) invade dunes/cliffs/wetlands in Australia, (2)listed as a invasive species in California, USA (3)An invasive pest in Tasmania, also a problem of unknown importance in Queensland and New South Wales [coastal areas, not on CalEPPC list]

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

no evidence

4.03

no evidence

4.04

http://ohioline.osu.edu/hyg-fact/1000/1031.html

Heavily Damaged by rabbits

4.05

no evidence

4.06

(1) http://nt.ars-grin.gov/SBMLWeb/homehtml.cfm
(2) Rao, V. G.; Yadav, B. R. D. (1995) Some hitherto undescribed fungal diseases on ornamental plants. Journal of the Annamalai University. Part B, Sciences, 1995, Vol.37, pp.79-86, 5 ref.
(3) Koike, S. T.; Tidwell, T. E.; Kosta, K. L. (1988) First report of powdery mildew (Oidiopsis taurica ) of gazania. Plant Disease, 1988, Vol.72, No.6, p.546, 1 ref.

(1) Rhizoctonia solani, Rhizoctonia sp., Sclerotinia sclerotiorum, Sphaerotheca fusca [all are generalist]
(2) Phyllosticta gazaniae on Gazania splendens [a generalist]
(3) powdery mildew (Oidiopsis taurica ) [a generalist]

4.07

no evidence

4.08

http://66.102.7.104/search?q=cache:DB4yhibWE1AJ:www.walterandersen.com
/pdf/Firewise.pdf+Gazania+rigens+var.+leucolaena&hl=en&client=firefox-a

Moderate Fire Retarding 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 1-887215-07-8. (2)http://www.desert-tropicals.com/Plants/Asteraceae/Gazania_Daybreak.html (3)http://www.ci.santa-barbara.ca.us/departments/community_development/forms/public_works/Plants_for_Parkways.pdf

(1)Soil Condition Sandy, neutral, tolerates salt, drought tolerant, humidity intolerant (2)light sandy soil (3)Grows in any soil (GAZANIA RIGENS LEUCOLAENA (TRAILING GAZANIA))

4.11

http://ag.arizona.edu/pubs/garden/az1110.pdf

creeping perennial

4.12

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

a groundcover

5.01

terrestrial

5.02

a perrenial herb, Asteraceae

5.03

a perrenial herb

5.04

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

Root Form: fibrous

6.01

no evidence

6.02

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

Propagation: cuttings; seeds

6.03

http://www.ci.santa-barbara.ca.us/departments/community_development/
forms/public_works/Plants_for_Parkways.pdf

New hybrids have larger flowers & are resistant to die back, bloom longer. [not natural hybrids]

6.04

http://easttexasgardening.tamu.edu/tips/flowers/gazania.html

If you deadhead the flowers and toss them where you want more, they will re-seed readily.

6.05

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-8.
(2) Vicidomini, S. (1998) Biology of Xylocopa (Xylocopa) violacea (Linnaeus, 1758) (Hymenoptera: Apidae): interesting observations and records in the Emerald Coast and neighbouring areas (Sassari, Sardinia). [FT: Biologia di Xylocopa (Xylocopa) violacea (Linneo, 1758) (Hymenoptera: Apidae) : interessanti osservazioni e segnalazioni in Costa Smeralda e zone limitrofe (Sassari, Sardegna).] Giornale Italiano di Entomologia, 1998, Vol.9, No.48, pp.155-158, 19 ref.

(1) Attracts butterflies
(2) AB: The foraging behaviour on four flower species is described for Xylocopa violacea in the Emerald Coast (Sassari, Sardinia). Only females forage on Gazania splendens [G. rigens ] and G. longiscapa in August, they collect pollen by "buzz-pollination". [appears to be a typical Asteraceae flower, open, insect pollinated]

6.06

http://www.environment.sa.gov.au/coasts/coastcare/plants.pdf

A very aggressive perennial herb with creeping stems that root at the nodes.

6.07

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

These plants are often grown as annuals in colder areas.

7.01

http://www.dpiwe.tas.gov.au/inter.nsf/Attachments/SLEN-5PBUSN/$FILE/Coastal%20Weed%20of%20Tasmania%20booklet.pdf

dumped garden waste

7.02

an oranamental

7.03

no evidence

7.04

http://www.dpiwe.tas.gov.au/inter.nsf/Attachments/SLEN-5PBUSN/$FILE/Coastal%20Weed%20of%20Tasmania%20booklet.pdf

Dispersal: wind,water and dumped garden waste

7.05

http://www.dpiwe.tas.gov.au/inter.nsf/Attachments/SLEN-5PBUSN/$FILE/Coastal%20Weed%20of%20Tasmania%20booklet.pdf

Dispersal: wind,water and dumped garden waste

7.06

no evidence

7.07

no evidence

7.08

no evidence

8.01

http://www.earthlygoods.com/wildflowers/gazania.html

Seeds per lb: 125,000 [possibly yes, small seeds]

8.02

http://wholesale.thompson-morgan.com/uk/es/product/7999/1

Propagate at 20c and germination should take place after 10 to 14 days [show no dormancy]

8.03

no evidence

8.04

(1)http://www.environment.sa.gov.au/coasts/coastcare/plants.pdf (2)http://ww2.lafayette.edu/~danielss/calif.html

(1)"A very aggressive perennial herb with creeping stems that root at the nodes." (2)Trim if looks untidy.

8.05

no evidence