One of the mysteries of the English language finally explained.
Definition of mountain daisy in English:
mountain daisy
noun
1NZ. Any of various plants of the genus Celmisia (family Asteraceae (Compositae)), chiefly having flowers with yellow discs and white rays.
2US. Any of several plants of the family Asteraceae (Compositae) growing in mountainous country; especially either of two fleabanes, Erigeron coulteri and E. peregrinus, and hoary blackfoot, Melampodium cinereum.
Origin
Late 18th century (in an earlier sense). From mountain + daisy.