Please don't call this Primrose. It is Evening Primrose (Oenothera), because it's yellow like a Primrose and it comes out in the evening (usually). Oenothera is NOT a member of the Primrose Family (Primulaceae). It's a member of a completely different family (Onagraceae). If you call it just Primrose, people will sometimes ignore it, thinking you do mean Primrose.
Mary, You are right, oenethera is the correct family, the regional names have confused a few traders when I have offered them and they have wanted the bright Florist primrose, that I plant after the spring flowers have faded. Those primose come back year after year for me also.