Linaria dalmatica ssp. dalmatica
Colorado Dept. of Agriculture Class B
Aliases: Balkan toadflax, broadleaf toadflax, wild snapdragon, smooth toadflax
Flowers/Fruit: Seeds Mature July – September. (Oct. after the 1st year)
Flowers: Snapdragon type, bright yellow, tinged with orange, 1-1/2″ long spur. The upper lip is 2-lobed and the lower is 3-lobed.
Bloom: May – August
Stem: Upright, branching toward the top up to 3-4 ft. tall. A single toadflax plant contains from 1 to 25 vertical, Floral stems which are thick-walled and somewhat woody. Prostrate stems are tolerant to freezing.
Leaves: Light to bluish-green waxy leaves are broad, alternate, ovate, sometimes heart-shaped and upper leaves clasp the stem (an important difference from yellow toadflax). Leaves get progressively smaller up the stem.
Root: Roots may grow 20 inches deep or more and lateral roots may extend 10 ft. from the parent plant. Very aggressive.
Reproduce: By seed (500,000 seeds or more/plant) as well as by a horizontal or creeping root system. Seeds are irregular in shape, tan-gray and 1/24″ to 1/16″ across.
Seed Viable: 10 Years
Mechanical Control: The combination of spraying and seeding competitive grasses control Dalmatian Toadflax better than spraying alone. Hand pulling or digging up the roots will need to be done for an average of 6 years. Plants will re-sprout from root fragments. Spray at flowering or in the fall.
Interesting Facts: It was introduced into the Western US in 1874. Broad leaved Dalmatian Toadflax (L. dalmatica) has been cultivated as an ornamental plant for at least 400 years. Used for centuries as a folk remedy and a dye. Extensive root system out competes other plants for nutrients and water. Contains toxic chemicals that can cause liver damage in grazing animals.
Dalmatian Toadflax differs from Yellow Toadflax principally in being larger and having different shaped leaves.
In Colorado, Dalmatian Toadflax shoot density increased over 1,200 percent in six years at one location, and 190 percent over 3 years at another.