Hartweg's sundrops (Oenothera toumeyi)
Same genus
- Kunth's evening primrose (Oenothera kunthiana)
- Pale evening primrose (Oenothera pallida)
- Fourpoint evening primrose (Oenothera rhombipetala)
- Narrowleaf evening primrose (Oenothera tetragona)
- Evening primrose (Oenothera biennis)
- Flaming Gorge evening primrose (Oenothera acutissima)
- Longflower evening primrose (Oenothera affinis)
- Whitest evening primrose (Oenothera albicaulis)