Pacific hemlock vs western hemlock

Pacific hemlock and western hemlock both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pacific hemlock	Yes	No	No	No
western hemlock	Yes	No	No	No

As nouns, Pacific hemlock and western hemlock are synonyms defined as:

Pacific hemlock and western hemlock: tall evergreen of western North America; commercially important timber tree

Other synonyms of Pacific hemlock include Tsuga heterophylla, west coast hemlock.

Pacific hemlock (noun)	western hemlock (noun)
tall evergreen of western North America; commercially important timber tree	tall evergreen of western North America; commercially important timber tree