Great St. Johnswort (Hypericum ascyron L.)

Also classified as Hypericum pyramidatum Aiton (refers to ssp. pyramidatum).

Some sources, particularly horticultural ones, separate Hypericum pyramidatum as its own species; we follow the convention of POWO, which most other authorities follow, in treating this as a subspecies, Hypericum ascyron ssp. pyramidatum (Aiton) N.Robson. In this treatment, the species Hypericum ascyron has three subspecies, but only one of them, ssp. pyramidatum, occurs in North America, where it is native. The other two are native to Asia and have never been reported in North America.