blood line vs stemma

blood line and stemma both are nouns.

Word	Noun	Adjective	Verb	Adverb
blood line	Yes	No	No	No
stemma	Yes	No	No	No

As nouns, blood line and stemma are synonyms defined as:

Other synonyms of blood line include ancestry, blood, bloodline, descent, line, line of descent, lineage, origin, parentage, pedigree, stock.

blood line (noun)	stemma (noun)
the hereditary derivation of an individual	an eye having a single lens
	the hereditary derivation of an individual
	a tree diagram showing a reconstruction of the transmission of manuscripts of a literary work