Calylophus serrulatus var. spinulosus (Torrey & A. Gray) Shinners
Calylophus serrulatus var. spinulosus (Torrey & A. Gray) Shinners is a synonym sensu FNA Ed. Comm., 2021 of:
Oenothera serrulata Nuttall, an accepted species name sensu FNA Ed. Comm., 2021.