A mountain flower is an item that can be picked up from the environment.
Mountain flowers spawn in northern Cantermore. Prior to Open Server Event 10, they only appeared among the trees in an area underneath the airship platform (and portal to Cloudopolis) mixed in with smooth rocks.
During OSE 10, two additional areas were discovered to be spawning mountain flowers, both adjacent to the eastern end of the river that separates the Palace grounds from the rest of the city. One is on the upper switchback level leading to the airship platform. The other is on the south bank, near a mountain waterfall.