purple beech vs copper beech

purple beech and copper beech both are nouns.

Word	Noun	Adjective	Verb	Adverb
purple beech	Yes	No	No	No
copper beech	Yes	No	No	No

As nouns, purple beech and copper beech are synonyms defined as:

purple beech and copper beech: variety of European beech with shining purple or copper-colored leaves

Other synonyms of purple beech include Fagus purpurea, Fagus sylvatica atropunicea, Fagus sylvatica purpurea.

purple beech (noun)	copper beech (noun)
variety of European beech with shining purple or copper-colored leaves	variety of European beech with shining purple or copper-colored leaves