Subgenus "Pentanthera" (deciduous azaleas) with its four sections was dismembered by eliminating two sections and redistributing the other two between the existing subgenera in clades B ("Hymenanthes") and C ("Azaleastrum"), although the name was retained in section "Pentanthera" (14 species) which was moved to subgenus "Hymenanthes". Of the remaining three sections, monotypic "Viscidula" was discontinued by moving "Rhododendron nipponicum" to "Tsutsusi" (C), while "Rhodora" (2 species) was itself polyphyletic and was broken up by moving "Rhododendron canadense" to section "Pentanthera" (B) and "Rhododendron vaseyi" to section "Sciadorhodion", which then became a new section of subgenus "Azaleastrum" (C).