pear tree vs Pyrus communis

pear tree and Pyrus communis both are nouns.

Word	Noun	Adjective	Verb	Adverb
pear tree	Yes	No	No	No
Pyrus communis	Yes	No	No	No

As nouns, pear tree and Pyrus communis are synonyms defined as:

pear tree and Pyrus communis: Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties

Other synonyms of pear tree include pear.

pear tree (noun)	Pyrus communis (noun)
Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties	Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties