Larix occidentalis vs larch

Larix occidentalis and larch both are nouns.

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

As nouns, larch is a hypernym of Larix occidentalis; that is, larch is a word with a broader meaning than Larix occidentalis:

Larix occidentalis: tall larch of western North America have pale green sharply pointed leaves and oblong cones; an important timber tree
larch: any of numerous conifers of the genus Larix all having deciduous needlelike leaves

Other hypernyms of Larix occidentalis include larch tree.

Larix occidentalis (noun)	larch (noun)
tall larch of western North America have pale green sharply pointed leaves and oblong cones; an important timber tree	any of numerous conifers of the genus Larix all having deciduous needlelike leaves
	wood of a larch tree