SilverBirds
Lurking
Welcome to BYC!
As some of the others said, Americana is just another name for Easter Eggers. Easter Eggers are any chickens that lays blue/green/pink eggs or carries the gene for it. Since they don't aren't an actual breed they come in every shape, size, and color. Ameraucanas are an actual breed. They come in certain colors and have a SOP (Standard of Perfection). Most EEs do have Ameraucana blood in them, hence the beards. You can read more about the difference in this Article.
As some of the others said, Americana is just another name for Easter Eggers. Easter Eggers are any chickens that lays blue/green/pink eggs or carries the gene for it. Since they don't aren't an actual breed they come in every shape, size, and color. Ameraucanas are an actual breed. They come in certain colors and have a SOP (Standard of Perfection). Most EEs do have Ameraucana blood in them, hence the beards. You can read more about the difference in this Article.