Pacific Island Ecosystems at Risk (PIER)


Linaria dalmatica


RISK ASSESSMENT RESULTS: High risk, score: 17


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments

Linaria dalmatica (L.) Mill. Family - Plantaginaceae (formerly Scrophulariaceae) Common Names(s) - Balkan toadflax, broadleaf toadflax, Dalmation toadflax, linaria-dalmatica. Synonym(s) - Antirrhinum dalmaticum L. (basionym), Linaria genistifolia subsp. dalmatica

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

n

0

1.02

Has the species become naturalized where grown?

y=1, n=-1

1.03

Does the species have weedy races?

y=-1, n=-1

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

0

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

1

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

n

0

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

1

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

y

1

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

y

2

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

1

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

y

1

4.05

Toxic to animals

y=1, n=0

y

1

4.06

Host for recognized pests and pathogens

y=1, n=0

n

0

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

n

0

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

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

1

4.11

Climbing or smothering growth habit

y=1, n=0

n

0

4.12

Forms dense thickets

y=1, n=0

n

0

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

n

0

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

n

-1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

1

1

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

-1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

y

1

7.05

Propagules water dispersed

y=1, n=-1

y

1

7.06

Propagules bird dispersed

y=1, n=-1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

-1

7.08

Propagules survive passage through the gut

y=1, n=-1

y

1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

1

8.02

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

y=1, n=-1

y

1

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

1

8.05

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

y=-1, n=1

Total score:

17

Supporting data:

Notes

Source

1.01

No evidence.

 

1.02

1.03

2.01

(1) Native to: Iran; Turkey; Albania; Bulgaria; Former Yugoslavia; Greece. (2) Seeds require cold stratification to germinate.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?102284#syn [Cited 2009 October 27]. (2) Baskin, C.C., Baskin, J.M., 2001. Seeds Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, San Diego.

2.02

(1) Native to: Iran; Turkey; Albania; Bulgaria; Former Yugoslavia; Greece. (2) Seeds require cold stratification to germinate.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?102284#syn [Cited 2009 October 27]. (2) Baskin, C.C., Baskin, J.M., 2001. Seeds Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, San Diego.

2.03

(1) L. dalmatic grows from sea level up to 2,800 meters. It has a tolerance to low temperatures and coarse soils.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

2.04

(1) No evidence of naturalization in tropical or subtropical climates.

(1) http://www.hear.org/gcw/species/linaria_dalmatica/ [Cited 2009 October 27]. [no record of naturalization in Hawaii at the Herbarium Pacificum]

2.05

(1) L. dalmatica was first reported in North America in 1894. It was being grown as an ornamental. L. dalmatica is classified as a weed in Europe, Russia, Canada, and the United States. (2) L. dalmatica has been cultivated since the 16th century and has been widely distributed around the world.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.nd.edu/~underc/west/education/documents/
RossJ_2006_recoveryofDalmatianToadflaxLinariadalmaticaandnativegrassesafterTordonapplication.pdf [Cited 2009 October 28].

3.01

(1) L. dalmatica is classified as a weed in Europe, Russia, Canada, and the United States.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

3.02

(1) Linaria dalmatica rapidly infests open sites. They are found along roadsides, fences, range lands, croplands, clear cuts and pastures. L. dalmatica can significantly reduce crop yields and stress native communities.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

3.03

(1) Linaria dalmatica rapidly infests open sites. They are found along roadsides, fences, range lands, croplands, clear cuts and pastures. L. dalmatica can significantly reduce crop yields and stress native communities. (2) L. dalmatica is a concern in pastures and rangelands, as well as natural areas, where it may outcompete native species. Herbicides used to control L. dalmatica in rangelands in the United States include dicamba, glyphosate, imazapyr, picloram and triclopyer.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.nd.edu/~underc/west/education/documents/
RossJ_2006_recoveryofDalmatianToadflaxLinariadalmaticaandnativegrassesafterTordonapplication.pdf [Cited 2009 October 28].

3.04

(1) Linaria dalmatica rapidly infests open sites. They are found along roadsides, fences, range lands, croplands, clear cuts and pastures. L. dalmatica can significantly reduce crop yields and stress native communities. Linaria is an ineffective competitor for soil moisture with established perennials and winter annuals. However, once established it can suppress other vegetation. L. dalmatica can form colonies and out compete native grasses and perennials, altering the species composition of natural communities. (2) "L. dalmatica is currently in an exponential growth phase of invasion in Montana, making it a considerable threat to resource conservation in this state." L. dalmatica is adapted to a wide range of habitats. It is most problematic in dry, open grassland and forest sites, along roadsides and disturbed sites with coarse well draining soils.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://msuextension.org/ruralliving/Dream/PDF/Weed/dalmatian_toadflax.pdf [Cited 2009 October 28].

3.05

(1) Linaria vulgaris is a invasive weed in AK, CO, CT, MI, MT, NJ, OR, VA, WA, WI, WV, and WY (United States). It occurs in roadsides, waste areas, rangeland, pastures, cultivated fields, meadows, forest edges and gardens. It crowds out other vegetation. Its high seed production and rhizomatous habit make eradication difficult.

(1) http://na.fs.fed.us/fhp/invasive_plants/weeds/butter-and-eggs.pdf [Cited 2009 October 28].

4.01

(1) No spines, thorns or burrs.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 28].

4.02

Unknown

4.03

(1) Not parasitic.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 28].

4.04

(1) Linaria dalmatica is unpalatable to livestock. (2) Linaria dalmatica is not known to be heavily grazed by any native animal species. Cattle usually avoid it, as it is distasteful or poisonous.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

4.05

(1) L. dalmatica contains a poisonous glucoside that is mildly poisonous to livestock.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

4.06

No evidence.

 

4.07

(1) No evidence of toxicity or allergies. (2) No evidence.

(1) http://www.ncbi.nlm.nih.gov/sites/entrez [Cited 2009 October 28]. (2) http://toxnet.nlm.nih.gov/cgi-bin/sis/search [Cited 2009 October 28].

4.08

(1) It is unclear how Linaria dalmatica affects fire regimes in native ecosystems.

(1) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

4.09

(1) Linaria dalmatica can tolerate moderate amounts of shade, it is more common in open areas. At Yellowstone National Park, Linaria dalmatica was found under a range of canopy cover from 0 to 85%.

(1) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

4.10

(1) Linaria dalmatica can grow on sandy or gravely soil on roadsides, railroads, pastures, cultivated fields, range lands and clear cuts. It can tolerate a range of coarse textured soils. (2) L. dalmatica is found in well-drained, coarse textured soils, varying from coarse gravels to sandy loams, but can be found in heavier soils in North America.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

4.11

(1) Linaria dalmatica is a perennial herb. Plants can grow to be between 0.8 - 1.5 m tall. A plant contains 1-25 vertical floral stems. The taproot may penetrate one meter into the soil. Horizontal roots grow to b several meters long, and can develop adventitious buds that can form independent plants.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

4.12

(1) Linaria dalmatica rapidly infests open sites. They are found along roadsides, fences, range lands, croplands, clear cuts and pastures. L. dalmatica can significantly reduce crop yields and stress native communities. Linaria is an ineffective competitor for soil moisture with established perennials and winter annuals. However, once established it can suppress other vegetation. L. dalmatica can form colonies and out compete native grasses and perennials, altering the species composition of natural communities. [forms colonies but not dense thickets]

1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

5.01

(1) Linaria dalmatica is a perennial herb. Plants can grow to be between 0.8 - 1.5 m tall. A plant contains 1-25 vertical floral stems. The taproot may penetrate one meter into the soil. Horizontal roots grow to b several meters long, and can develop adventitious buds that can form independent plants.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

5.02

(1) Scrophulariaceae.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

5.03

(1) Linaria dalmatica is a perennial herb. Plants can grow to be between 0.8 - 1.5 m tall. A plant contains 1-25 vertical floral stems. The taproot may penetrate one meter into the soil. Horizontal roots grow to b several meters long, and can develop adventitious buds that can form independent plants.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

5.04

(1) Linaria dalmatica is a perennial herb. Plants can grow to be between 0.8 - 1.5 m tall. A plant contains 1-25 vertical floral stems. The taproot may penetrate one meter into the soil. Horizontal roots grow to b several meters long, and can develop adventitious buds that can form independent plants.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

6.01

No evidence.

 

6.02

(1) Linaria dalmatica seed viability and germination rates are variable. Viability is affected by resource limitation, seed predators, and pollination limitation.

(1) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

6.03

Unknown (1) Linaria dalmatica has hybridized with Linaria genistifolia in the lab.

(1) http://msuextension.org/ruralliving/Dream/PDF/Weed/dalmatian_toadflax.pdf [Cited 2009 October 28]

6.04

(1) Self-incompatible.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

6.05

(1) The two most important pollinators of L. dalmatica are bumble bees and halictid bees.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

6.06

(1) Linaria dalmatica is a perennial herb. A plant contains 1-25 vertical floral stems. The taproot may penetrate one meter into the soil. Horizontal roots grow to b several meters long, and can develop adventitious buds that can form independent plants.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

6.07

(1) Vegetative reproduction from root buds can occur as early as 2-3 weeks after germination. Buds can grow their own root and shoot systems, and become independent plants the next year. (2) In a phenological study of L. dalmatica over 5 years in Spokane, Washington it was observed that some seeds could germinate in the same year they were produced.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Robocker, W.C., 1970. Seed Characteristics and Seedling Emergence of Dalmatian Toadflax. Weed Science 18, 720-725.

7.01

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. (2) Seed dispersal by farm machinery is an important mode of dispersal in agricultural areas.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html [Cited 2009 October 27].

7.02

(1) Linaria dalmatica was probably introduced to North America as an ornamental and is still used as a garden plant in many areas. (2) L. dalmatica is cultivated for ornamental, medicinal and cultural purposes.

(1) http://akweeds.uaa.alaska.edu/pdfs/potential_species/bios/Species_bios_LIDA.pdf [Cited 2009 October 27]. (2) http://msuextension.org/ruralliving/Dream/PDF/Weed/dalmatian_toadflax.pdf [Cited 2009 October 28].

7.03

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. [not grown with produce although it does occur in pastures]

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

7.04

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. (2) Observational studies over several years indicated that wind is the primary means of dispersal for L. dalmatica.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Robocker, W.C., 1970. Seed Characteristics and Seedling Emergence of Dalmatian Toadflax. Weed Science 18, 720-725.

7.05

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. (2) Microscopic examination of cattle manure showed that many L. dalmatica seeds pass through the gastrointestinal tracts of cattle. The viability of the seeds was confirmed in the greenhouse. Field observations showed seedlings emerging from cow manure and soil adjacent, where seeds could have washed to the soil with rain. (3) A review by Saner, Marc A.; Clements, David R.; Hall, Michael R.; [and others]. 1995. The biology of Canadian weeds. 105. Linaria vulgaris Mill. Canadian Journal of Plant Science. 75(2): 525-537, suggests that Linaria dalmatica may be dispersed by ants, water, birds, and rodents. [unable to get the article to confirm].

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Robocker, W.C., 1970. Seed Characteristics and Seedling Emergence of Dalmatian Toadflax. Weed Science 18, 720-725. (3) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html[Cited 2009 October 27].

7.06

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. (2) A review by Saner, Marc A.; Clements, David R.; Hall, Michael R.; [and others]. 1995. The biology of Canadian weeds. 105. Linaria vulgaris Mill. Canadian Journal of Plant Science. 75(2): 525-537, suggests that Linaria dalmatica may be dispersed by ants, water, birds, and rodents. [unable to get the article to confirm].

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://www.fs.fed.us/database/feis/plants/forb/linspp/all.html[Cited 2009 October 27].

7.07

[No means of attachment]. (1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

7.08

(1) Egg-shaped to round capsules 4-10 mm long by 4-8 mm wide. Seeds are angular, slightly winged, and 1-2 mm long. (2) Microscopic examination of cattle manure showed that many L. dalmatica seeds pass through the gastrointestinal tracts of cattle. The viability of the seeds was confirmed in the greenhouse.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].

8.01

(1) L. dalmatica can produce up to 500,000 seeds annually. (2) A large plant will produce a half a million seeds under good conditions.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Robocker, W.C., 1970. Seed Characteristics and Seedling Emergence of Dalmatian Toadflax. Weed Science 18, 720-725.

8.02

(1) Seeds of L. dalmatica can remain dormant for up to 10 years. (2) "Observations on seed longevity under natural conditions at Spokane, WA. Indicated a possible field longevity of 10 years with a variable life span dependent on soil, weather and climate conditions."

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Robocker, W.C., 1970. Seed Characteristics and Seedling Emergence of Dalmatian Toadflax. Weed Science 18, 720-725.

8.03

(1) Permanent long term control can not be achieved by herbicides alone. L. dalmatica has a 10 year seed bank. The herbicides glyphosate, dicamba and picloram are considered effective for controlling L. dalmatica. Herbicides should be applied when the plants are flowering. (2) Results of herbicide trials on Linaria have been variable with very good control in some treatments and practically no control in other applications of the same treatment.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) http://msuextension.org/ruralliving/Dream/PDF/Weed/dalmatian_toadflax.pdf [Cited 2009 October 28].

8.04

(1) Burning is not recommended as a control method. The deep taproot of L. dalmatica protects it from fire damage. Areas that have been recently burned are susceptible to L. dalmatica invasion. (2) This study on the impacts fire on the spread of L. dalmatica indicated that severe fire may facilitate the spread of L. dalmatica in the first two years after the fire. Lower fire severities, typical of prescribed burn can facilitate the spread of L. dalmatica. (3) Cultivation will most likely spread root fragments and is not an effective control.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27]. (2) Dodge, R.W., Fulé, P.Z. 2008. Dalmatian toadflax (Linaria dalmatica) response to wildfire in a southwestern USA forest. (3) http://msuextension.org/ruralliving/Dream/PDF/Weed/dalmatian_toadflax.pdf [Cited 2009 October 28].

8.05

Unknown (1) "Five insects species have been approved by the USDA-APHIS-PPQ for release as biological control agents for Linaria genistifolia ssp. dalmatica and Linaria vulgaris. Anecdotal evidence to date suggests these insects have not been highly effective in controlling toadflax." These species are: Brachypterolus pulicarius, Calophasia lunula, Gymnetron antirrhini, Eteobalea serratella and Eteobalea intermediella.

(1) http://www.imapinvasives.org/GIST/ESA/esapages/documnts/linadal.pdf [Cited 2009 October 27].


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