Larix russica vs larch

Larix russica and larch both are nouns.

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

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

Larix russica: medium-sized larch of northeastern Russia and Siberia having narrowly conic crown and soft narrow bright-green leaves; used in cultivation
larch: any of numerous conifers of the genus Larix all having deciduous needlelike leaves

Other hypernyms of Larix russica include larch tree.

Larix russica (noun)	larch (noun)
medium-sized larch of northeastern Russia and Siberia having narrowly conic crown and soft narrow bright-green leaves; used in cultivation	any of numerous conifers of the genus Larix all having deciduous needlelike leaves
	wood of a larch tree