scale leaf vs foliage

scale leaf and foliage both are nouns.

Word	Noun	Adjective	Verb	Adverb
scale leaf	Yes	No	No	No
foliage	Yes	No	No	No

As nouns, foliage is a hypernym of scale leaf; that is, foliage is a word with a broader meaning than scale leaf:

scale leaf: a specialized leaf or bract that protects a bud or catkin
foliage: the main organ of photosynthesis and transpiration in higher plants

Other hypernyms of scale leaf include leaf, leafage.

scale leaf (noun)	foliage (noun)
a specialized leaf or bract that protects a bud or catkin	(architecture) leaf-like architectural ornament
	the main organ of photosynthesis and transpiration in higher plants