Larix siberica vs Larix russica

Larix siberica and Larix russica both are nouns.

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

As nouns, Larix siberica and Larix russica are synonyms defined as:

Larix siberica and Larix russica: medium-sized larch of northeastern Russia and Siberia having narrowly conic crown and soft narrow bright-green leaves; used in cultivation

Other synonyms of Larix siberica include Siberian larch.

Larix siberica (noun)	Larix russica (noun)
medium-sized larch of northeastern Russia and Siberia having narrowly conic crown and soft narrow bright-green leaves; used in cultivation	medium-sized larch of northeastern Russia and Siberia having narrowly conic crown and soft narrow bright-green leaves; used in cultivation