Dalmatian toadflax is a member of the Figwort family. It was introduced as an ornamental from Europe, and is rapidly invading dry range-land from 5,000 to 8,000 feet. It is a creeping perennial that closely resembles Yellow toadflax. The leaves are waxy, heart-shaped, and clasp the stem. The stems are two to four feet tall. The flowers are snapdragon-shaped, bright yellow, with orange centers.
Dalmatian toadflax is especially well adapted to arid sites and can spread rapidly once established. Because of its deep, extensive root stem, waxy leaf, and heavy seed production, this plant is difficult to manage.
For more info and how to control, check out the Colorado Department of Ag Fact Sheet