forest vs flora

forest and flora both are nouns.

As nouns, flora is a hypernym of forest; that is, flora is a word with a broader meaning than forest:

Other hypernyms of forest include vegetation, botany.

forest (noun)	flora (noun)
the trees and other plants in a large densely wooded area	all the plant life in a particular region or period
land that is covered with trees and shrubs	(botany) a living organism lacking the power of locomotion

forest (verb)	flora (verb)
establish a forest on previously unforested land