They have a longer bill than the purple finch. All titles on Purple Finch Productions. The purple finch was originally described by Johann Friedrich Gmelin in 1789. This bird belongs to the genus "Haemorhous", together with the purple finch and Cassin's finch. The purple finch population has declined sharply in the East due to the house finch. The purple finch ("Haemorhous purpureus") is a bird in the finch family, Fringillidae.