line of descent vs stemma

line of descent and stemma both are nouns.

Word	Noun	Adjective	Verb	Adverb
line of descent	Yes	No	No	No
stemma	Yes	No	No	No

As nouns, line of descent and stemma are synonyms defined as:

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

line of descent (noun)	stemma (noun)
the hereditary derivation of an individual	an eye having a single lens
the kinship relation between an individual and the individual's progenitors	the hereditary derivation of an individual
	a tree diagram showing a reconstruction of the transmission of manuscripts of a literary work