1923 4 49 Other secondary plants are..Missouri primrose, Megapterium missouriense.
1961 H. S. Irwin & M. M. Wills 164 The Flutter-mill, also known as Ozar-sundrop, Missouri-primrose, or Buttercup.
1998 (Nexis) 21 Apr. 3 The Missouri primrose (Oenothera macrocarpa) is the perfect easy-care plant for a sunny spot with thin, dry, rocky or sandy soil.