Yellow toadflax came from Eurasia. It is an aggressive invader of rangeland, roadsides, field edges, and waste areas. An extensive root system makes this weed difficult to control. It reproduces by seeds and roots.
This creeping herbaceous perennial weed grows to 2 feet tall. Leaves are 2.5 inches in length, and are narrow and pointed. Flowers are about 1 inch long, yellow with an orange throat, have long tails, and develop in dense, terminal clusters. They look similar to snap dragon flowers. Bloom is in late spring into summer. Fruits are small, 1/4 inch, two celled, berry-like capsules containing many seeds.
A few biocontrol agents are available and offer fair control. Herbicides can offer good control.