| Pachylophus prolatus | Oenothera marginata Nutt. ex Hook. & Arn. sect. Pachylophus |
| Pachylophus psammophilus | Oenothera psammophila (A.Nelson & J.F.Macbr.) Wagner et al. sect. Pachylophus |
| Pachylophus prolatus | Oenothera marginata Nutt. ex Hook. & Arn. sect. Pachylophus |
| Pachylophus psammophilus | Oenothera psammophila (A.Nelson & J.F.Macbr.) Wagner et al. sect. Pachylophus |