Fontinalis welchiana, a new species in the concave-leaved group of
Fontinalis restricted to Arkansas, Missouri, and Illinois, differs from
F. novaeangliae by its slender size, dimorphic leaves, erect and strongly concave branch leaves, and lightly papillose exostome with ventral
lamellae that are strongly rounded at the corners.
Fontinalis allenii is a synonym of
F. antipyretica var.
oreganensis.