dandelion green vs leafage

dandelion green and leafage both are nouns.

Word	Noun	Adjective	Verb	Adverb
dandelion green	Yes	No	No	No
leafage	Yes	No	No	No

As nouns, leafage is a hypernym of dandelion green; that is, leafage is a word with a broader meaning than dandelion green:

dandelion green: the foliage of the dandelion plant
leafage: the main organ of photosynthesis and transpiration in higher plants

Other hypernyms of dandelion green include foliage, leaf.

dandelion green (noun)	leafage (noun)
edible leaves of the common dandelion collected from the wild; used in salads and in making wine	the main organ of photosynthesis and transpiration in higher plants
the foliage of the dandelion plant