Historically, the Ericaceae included both subfamilies and tribes. In 1971, Stevens, who outlined the history from 1876 and in some instances 1839, recognised six subfamilies (Rhododendroideae, Ericoideae, Vaccinioideae, Pyroloideae, Monotropoideae, and Wittsteinioideae), and further subdivided four of the subfamilies into tribes, the Rhododendroideae having seven tribes (Bejarieae, Rhodoreae, Cladothamneae, Epigaeae, Phyllodoceae, and Diplarcheae). Within tribe Rhodoreae, five genera were described, "Rhododendron" L. (including "Azalea" L. pro parte), "Therorhodion" Small, "Ledum" L., "Tsusiophyllum" Max., "Menziesia" J. E. Smith, that were eventually transferred into "Rhododendron", along with Diplarche from the monogeneric tribe Diplarcheae.