Plant Assessment Form

Linaria dalmatica ssp. dalmatica

Synonyms: Linaria genistifolia ssp. dalmatica, Linaria dalmatica, Linaria dalmatica ssp. dalmatica, Antirrhimum dalmaticum

Common Names: dalmatian toadflax, broad-leaved toadflax, wild snapdragon

Evaluated on: 1/27/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Joe DiTomaso
Alison Stanton
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

Removed second scientific name, Linaria genistifolia ssp. dalmatica, and added it to the synonym line, 3/24/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Reviewed Scientific Publication
Impact?
Four-part score BBBU Total Score
B
1.2 ?Impact on plant community B. Moderate Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels B. Moderate Other Published Material
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
12 Total Score B
2.2 ?Local rate of spread with no management A. Increases rapidly Other Published Material
2.3 ?Recent trend in total area infested within state B. Increasing less rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal C. Low Other Published Material
2.6 ? Potential for natural long-distance dispersal D. None Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Other Published Material
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very low Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? B Reviewed Scientific Publication
Identify ecosystem processes impacted:

Plants are highly competitive for soil moisture.


Sources of information:

Rose, K. K., A. L. Hild, T. D. Whitson, D. W. Koch, and L. Van Tassel. 2001. Competitive effects of cool-season grasses on re-establishment of three weed species. Weed Technology 15(4): 885-891


Question 1.2 Impact on plant community composition,
structure, and interactions?
B Reviewed Scientific Publication
Identify type of impact or alteration:

Displaces existing plant communities through vegetative reproduction. Highly efficient in competing for moisture and usually emerges before competing species (1). Seedlings are less successful where dense stands of grasses are present, but this may not be very important as most of its competitive ability comes from the spread of roots. Plants are highly competitive for soil moisture with winter annuals and shallow-rooted perennials, and large colonies that displace desirable vegetation can develop in natural areas. The toadflaxes are especially problematic in the northwestern states, where thousands of acres of rangeland are heavily infested. Production of dalmation toadflax declines as seeded grasses increase (2). Plant competition was the main factor influencing seedling counts, suggesting that recruitment of Dalmation toadflax is limited by interspecific resource competition (3).


Sources of information:

1. Lajeunesse, S. 1999. Dalmatian and yellow toadflax. pp. 202-216 in Sheley, R.L., and J. K. Petroff. Biology and management of noxious rangeland weeds. Oregon State University Press, Corvallis, OR
2. Rose, K. K., A. L. Hild, T. D. Whitson, D. W. Koch, and L. Van Tassel. 2001. Competitive effects of cool-season grasses on re-establishment of three weed species. Weed Technology 15(4): 885-891
3. Grieshop, M. J. and R. M. Nowierski . 2002. Selected factors affecting seedling recruitment of dalmatian toadflax. Journal of Range Management 55(6): 612-619.


Question 1.3 Impact on higher trophic levels? B Other Published Material
Identify type of impact or alteration:

Loss of forage can impact big-game species. Deer browse dalmation toadflax, but it is not know to be heavily used by any native species (1). Livestock typically avoid grazing toadflax; thus, livestock carrying capacity is much reduced in areas where there are large, dense populations of toadflax. Both species contain quinazoline alkaloids that could possibly pose toxicity problems if ingested in sufficient quantity, but intoxications of livestock have not been reported.


Sources of information:

1. Lajeunesse 1999
DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


Question 1.4 Impact on genetic integrity? U

There is one native (L. canadensis, blue toadflax) and several introduced species of Linaria in California (1). A hybrid between L. dalmatica and L. vulgaris was found in Modoc County (2), so presumably it could also hybridize with L. canadensis.


Sources of information:

1. Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA
2. Vujnovic K., and R.W. Wein R.W. 1997. The Biology of Candadian Weeds. 106. Linaria dalmatica (L.) Mill. Canadian Journal of Plant Science 77(3): 483-401.


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
A Other Published Material
Describe role of disturbance:

All papers describe it as occurring in disturbed habitats, but it is frequently invading undisturbed sites. Many populations have evolved with, and are adapted to, periodic disturbances of agriculture. Can also establish in naturally-occurring disturbances (1). In California, occurs in a range of disturbed areas (see 3.1). In Washington, dalmation toadflax seedings were never found on non-cultivated areas, indicating it may be unable to become established in heavy stands of vegetation (2). See also question 1.2.


Sources of information:

1. Lajeunesse 1999
2. Gates D.H., Robocker W.C. 1961?. Revegetation with adapted grasses in competition with dalmation toadflax and St. Johnswort. Scientific Paper 1943, Washington Agricultural Experiment Station, Pullman, WA


Question 2.2 Local rate of spread with no management? A Other Published Material
Describe rate of spread:

Can expand at a rapid rate in many locations of the west, including California.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


Question 2.3 Recent trend in total area infested within state? B Observational
Describe trend:

Spreading, but not rapidly. Some control efforts by CDFA keep populations down.


Sources of information:

DiTomaso, observational.


Question 2.4 Innate reproductive potential? A Reviewed Scientific Publication
Describe key reproductive characteristics:

Deep-rooted, short-lived (3-5 yrs) herbaceaous perennial (1). Insect-pollinated and self-incompatible (2). Individual patches can persist 13 yrs or more. Flowering begins in June and continues until September or October, but can occur earlier in warmer habitats. Within nine weeks after germination, seedling roots have vegetative buds that can give rise to new, independent plants. Roots of mature plants can reach to 10 ft deep (1). Produces seeds for 3 months. A large plant can produce 500,000 seeds. >90% germination can be obtained from 2 or 3-yr-old seeds in the lab. Seed longevity under field conditions can be up to 10 yrs (3).


Sources of information:

1. Lajeunesse 1999
2. Vujnovic, K. and R. W. Wein 1997. The biology of Canadian weeds: 106. Linaria dalmatica (L.) Mill. Canadian Journal of Plant Science 77(3): 483-491.
3. Robocker, W. C. 1970. Seed characteristics and seedling emergence of Dalmatian toadflax. [Linaria dalmatica]. Weed Science 18(6): 720-725.


Question 2.5 Potential for human-caused dispersal? C Other Published Material
Identify dispersal mechanisms:

Was used as a garden plant, although is not currently listed in the Sunset Western Garden Book (1). On farm land, root pieces can be spread by farm equipment. Seeds can be tranported in mud on bikes, tires, feet of livestock, etc. (2). However, most seed fall directly below parent plant.


Sources of information:

1. Brenzel, K. N. 2001. Sunset Western Garden Book. Sunset Publishing Company, Menlo Park, CA.
2. Lajeunesse 1999


Question 2.6 Potential for natural long-distance dispersal? D Other Published Material
Identify dispersal mechanisms:

Seeds can be dispersed by wind, but 80-90% of seeds fall within 0.5m of the parent plant (1), so long distance dispersal does not sound common.


Sources of information:

1. Lajeunesse 1999


Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

Native to the Mediterranean. Serious problem in rangeland of the northwestern U.S. Listed as a noxious weed in Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, South Dakota, Washington, Wyoming (1). Also invasive in Canada, the British Isles, the mideast , and other areas around the world.Dalmatian toadflax and yellow toadflax were brought to North America from Europe as garden ornamentals in the mid- to late-1800s and mid-1600s, respectively, and have since widely escaped cultivation.


Sources of information:

1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Other Published Material

Occurs throughout California, except Great Basin and deserts, to 1000m. Grows in disturbed open sites, fields, pastures, rangeland, forest clearings, roadsides, crops. Can tolerate a broad range of climatic conditions and soil types, but grows best in cool, semi-arid climates, and on dry, coarse soils at neutral to slightly alkaline pH. Does NOT occur in the following counties: Amador, Fresno, Imperial, Kings, Marin, Mariposa, Orange, Riverside, San Benito, Santa Clara, Santa Cruz, Stanislaus, Sonoma, Sutter, Tuolumne, Yuba.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


Question 3.2 Distribution/Peak frequency? D Observational
Describe distribution:

Not common in state, mainly found in northern areas.


Sources of information:

DiTomaso, observational.
Joanna Clines, Sierra National Forest, pers. obs.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
Seeds remain viable in soil for three or more years Yes
Viable seed produced with both self-pollination and cross-pollination No
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 8
Total unknowns: 0
Total score: A?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrub
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrubD, < 5%
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grassland
Great Basin grasslandD, < 5%
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forestD, < 5%
upper montane coniferous forestD, < 5%
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): B
Distribution (highest score): D

Infested Jepson Regions

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