Yellow toadflax is a creeping perennial 12 to 24" tall. Leaves are pale green, narrow, 2.5" long and pointed at both ends.
Flowers are 1" long with a bearded orange throat. Similar to "snapdragons or butter and eggs", common garden flowers.
This plant was introduced into the US as an ornamental in the mid-1800's. An extensive root system makes it an aggressive invader of ROW, rangelands, waste places and cultivated fields. It is difficult to control once established
Information adapted from "Weeds of the West" by Tom Whitson