A matriarch was the leader of any specifically female-ruled culture. The most prominent example of this was on Dathomir, where Zalem was matriarch for a time.
Also, on Saheelindeel there was a matriarch ruler during Han Solo's visit, in 1 BBY.
On Honoghr, the planet of the Noghri, each clan had a matriarch, called Maitrakh. This person was the storyteller, leader, and lore keeper of the clan.