I agree with Lynne - look at www.wildseedfarms.com in Fredericksburg, Tx. They have seeds for Evening Primrose (oenothera lamarckiana), Missouri Primrose (O. missouriensis), and Showy Primrose (O. speciosa).
All of these come up in my front pastures and they are delightful. Not triloba, but still very pretty.
