Common toadflax, butter-and-eggs, yellow toadflax
All the western states (non-native); classed as noxious. More common in northern states
Between 1 and 3 feet
Open ground; grasslands, roadsides, disturbed sites
Narrow, linear, alternate, undivided, up to 4 inches long
June to September
The unusual, bicolored flowers of linaria vulgaris consist of a projecting, 2 lobed upper lip surrounded by a shorter, three-lobed lower lip, which extends backwards into a curved spur. The middle of the lower lip is colored bright orange, and is hairy, while the remainder of the corolla is pale yellow. Flowers grow in small clusters on slender, unbranched stems that have many thin, narrow leaves most of the way along. The species was introduced from Europe and has spread all across the US, inhabiting disturbed ground like roadsides, dunes and field margins.