old man of the mountain, alpine sunflower, Tetraneuris grandiflora, Hymenoxys grandiflora(noun)

whitish hairy plant with featherlike leaves and a few stout stems each bearing an especially handsome solitary large yellow flower head; mountainous regions north central United States

Old Man of the Mountain

a name given to Hassan ben Sabbah, the founder in the 11th century and his successors of a formidable Mohammedan dynasty in Syria, whose residence was in the mountain fastnesses of the country, and whose following was known by the name of Assassins (q. v.).