I know that angelonia is often called summer snapdragon.

Hi Sarah,

Could it possibly be perennial snapdragon, Antirrhinum braun-blanquetti (a/k/a braun-blanquett) which is a very pale yellow? If so, it's marginally hardy here in z5, so I kind of assume it would work in Texas but have no way of knowing for sure--but, hey, if they're free, give it a try---what have you got to loose!

Good luck,
Skybird

Here is a link that might be useful:

I don't know about a false snapdragon. We have grown various colors of snapdragons for years. Many die during the winters here in Texas zone 6b, but they are a perennial, and those planted in protected areas will live through the winter. They also come up from seed, but colors may change because of cross-pollination.

In the mountains of New Mexico and southwestern Colorado, the yellow ones are a common wildflower.