Dalmation Toadflax
Scientific Name: Linaria genistifolia

History/Origin
          Dalmatian toadflax is a native of southeastern Europe's Mediterranean region. It was cultivated as an ornamental in Europe for nearly four centuries and was brought to the western coast of North America for that purpose (1874).

Biology/Ecology
          A single plant can produce up to 500,000 seeds from late June until early October. Seeds usually develop first in the lower flowers while the upper flowers may still be budding. Although seeds may lay dormant in the soil for over 10 years, usually only 50% of them will germinate. Germination can occur in the Fall, but most develop in early Spring, usually on south-facing slopes first. As toadflax develops it becomes very competitive for available water, but while young it is vulnerable to dehydration and competition by other plants.

          First-year toadflax plants form prostrate rosettes, spending most of their energy establishing an extensive root system. Roots can grow 4-10 feet deep, and develop buds along their surface, capable of producing new shoots. This allows dalmatian toadflax plants to produce new shoots before native plants do, limiting resource availability, and ultimately crowding out other plants species.

          Dalmatian toadflax plants live an average of 3-5 years. Populations can disappear, "die out," and then return again a few years later from dormant seeds or living roots.

Known Impacts
Detrimental:
           Dalmatian toadflax will displace existing plant species and their associated animal life. Where grasses have been replaced there is a increase in surface runoff, erosion, and sediment yields in streams. Loss of forage can impact big game and domestic livestock carrying capacity, especially on winter range. The plant can be mildly toxic to cattle that eat it, but this is rare.

Beneficial:
           This plant has been used lightly as browse for deer and the seeds are used by some birds and rodents. Unlike wildlife, sheep will eat this as a major food source. On harsh, sparsely vegetated sites, toadflax can actually help stabilize the soil.

Potential Locations
          This plant usually invades disturbed open sites, especially areas that are grazed moderately to intensely (primarily by sheep). Dalmatian toadflax prefers well-drained coarse-textured soils, and becomes highly competitive in dry areas, particularly southern and southeastern facing slopes. Plants can be found along roadsides, in vacant lots, cemeteries, gravel pits, open fields, and rangeland. Once established, the condition of the existing native plants will have little impact in slowing the expansion of this plant.

Control/Management
          Control requires the use of several tools. Each population may require different treatments due to high genetic variability. Some of the most effective controls known are:
• Hand pulling for 6 years. This depletes the root reserves on small patches, preventing further vegetative growth. The site must be revisited and maintained for the next 10-15 years.
• Reseeding with a mix of competitive native plants. This can reduce seedling establishment, but will only slow established populations.
• Grazing should be deffered until late in the season. This allows desired native plants time to compete. Sheep are effective in suppressing stands and reducing seed production during flowering.
• Over six different parasitic insects species are currently being used with variable impacts.
• Herbicide success is variable, with chemical type and concentration often site-specific (example herbicides: Telar and Tordon 22K [look at herbicide label: free search]).