Piperia cooperi (S. Watson) Rydb. in Bull. Torrey Bot. Club 28(11): 636. 1901 sec. Soto-Arenas & al. 2007
- ≡Habenaria cooperi S. Watson in Proc. Amer. Acad. Arts 12: 276-277. 1877 syn. sec. Solano Gómez & al. 2020
- =Habenaria unalascensis (Spreng.) S. Watson in Proc. Amer. Acad. Arts 12: 277. 1877 syn. sec. Soto-Arenas & al. 2007
- =Piperia unalascensis (Spreng.) Rydb. in Bull. Torrey Bot. Club 28(5): 270. 1901 syn. sec. Solano Gómez & al. 2020