Larix occidentalis vs western larch

Larix occidentalis and western larch both are nouns.

Word	Noun	Adjective	Verb	Adverb
Larix occidentalis	Yes	No	No	No
western larch	Yes	No	No	No

As nouns, Larix occidentalis and western larch are synonyms defined as:

Larix occidentalis and western larch: tall larch of western North America have pale green sharply pointed leaves and oblong cones; an important timber tree

Other synonyms of Larix occidentalis include Oregon larch, western tamarack.

Larix occidentalis (noun)	western larch (noun)
tall larch of western North America have pale green sharply pointed leaves and oblong cones; an important timber tree	tall larch of western North America have pale green sharply pointed leaves and oblong cones; an important timber tree