orchard apple tree vs Malus pumila

orchard apple tree and Malus pumila both are nouns.

Word	Noun	Adjective	Verb	Adverb
orchard apple tree	Yes	No	No	No
Malus pumila	Yes	No	No	No

As nouns, orchard apple tree and Malus pumila are synonyms defined as:

orchard apple tree and Malus pumila: native Eurasian tree widely cultivated in many varieties for its firm rounded edible fruits

Other synonyms of orchard apple tree include apple.

orchard apple tree (noun)	Malus pumila (noun)
native Eurasian tree widely cultivated in many varieties for its firm rounded edible fruits	native Eurasian tree widely cultivated in many varieties for its firm rounded edible fruits