Liatris spicata (L.) Willd. - syn.Lacinaria spicata (L.) Kuntze; Liatris callilepis hort.; Serratula spicata L. - Asteraceae
(prairie) gay feather, (marsh) blazingstar, button snakeroot, (Ährige) Prachtscharte

Perennial herb, native to eastern North America, cultivated as garden flower around the world; flowers showy purple (pink or white in some cultivars).

Loiseleur-Deslongchamps,J.L.A., Herbier général de l’amateur. Deuxième Série, vol.1 t.80 (1839-50)
http://plantgenera.org/species.php?id_species=602065