Butter-and-Eggs, a non-native and, in some areas, invasive plant, has been added to the USWildflowers database (03/23/2019.) Scientific name is Linaria vulgaris. Photo below was taken along the Blue Ridge Parkway in southwest Virginia on Sep 01, 2014. Go to the Butter-and-Eggs detail page for more information and photos.

Butter-and-eggs – Linaria vulgaris