Because there is no geographical name derived from the family name "Kusunoki" in Kawachi Province, some insist that the clan served as low-level official of the Tokuso family of the Hojo clan and moved later to Kawachi (a territory of the Tokuso family of the Hojo clan), but others have different opinions, including one that states that that the clan originally came from Musashi Province (Kanto region).
河内国には楠木姓の由来となるような地名はなく、北条氏得宗家被官の一族で、得宗領の河内へ移ってきたとする説、武蔵国（関東地方）の出身であるとする説などがある。