Bot. Mag. 61: plate 3361. 1834.
Subspecies thalassaphila (Brandegee) W. Dietrich & W. L. Wagner differs from subsp. drummondii in a number of modally distinctive morphological features, especially floral tubes 2–3.5 cm, sepal tips 0.3–1 mm, capsules 2–4 cm × 2.5–5 mm in diameter and those, coupled with the great disjunction from the Atlantic coast of the United States and Mexico to the southern tip of Baja California, make it worthy of recognition. Oenothera drummondii is self-compatible and outcrossing.
s United States, n Mexico.
Subspecies 2 (1 in the flora).