Dionysius is the Son of his Mother because he issues from a matrilinear group.
But are we sure that there is only one type of matrilinear succession?
These are the languages of the south central group of tribes with a 2-class system and matrilinear descent.
Descent was matrilinear, and a society known as matriarchy existed, as contrasted to the later patriarchy.
They still have a strong element of descent in the matrilinear line and women aren't second-class citizens.
matrilineal mat·ri·lin·e·al (māt'rə-lĭn'ē-əl)
Relating to, based on, or tracing ancestral descent through the maternal line.