A number of closely related genera had been included together with "Rhododendron" in a former tribe, Rhodoreae. These have been progressively incorporated into "Rhododendron". Chamberlain and Rae moved the monotypic section "Tsusiopsis" together with the monotypic genus "Tsusiophyllum" into section "Tsutsusi", while Kron & Judd reduced genus "Ledum" to a subsection of section "Rhododendron". Then Judd & Kron moved two species ("Rhododendron schlippenbachii", "R. quinquefolium") from section "Brachybachii", subgenus "Tsutsusi" and two from section "Rhodora", subgenus "Pentanthera" ("R. albrechtii", "R. pentaphyllum") into section "Sciadorhodion", subgenus "Pentanthera". Finally Chamberlain brought the various systems together in 1996, with 1,025 species divided into eight subgenera. For a comparison of the Sleumer and Chamberlain schemata see Table 1 of Goetsch (2005).