In the later traditional classification, attributed to Chamberlain (1996), and as used by horticulturalists and the American Rhododendron Society, "Rhododendron" has eight subgenera based on morphology, namely the presence of scales (lepidote), deciduousness of leaves, and the floral and vegetative branching patterns, after Sleumer (1980). These consist of four large and four small subgenera. The first two subgenera ("Rhododendron" and "Hymenanthes") represent the species commonly considered as 'Rhododendrons'. The next two smaller subgenera ("Pentanthera" and "Tsutsusi") represent the 'Azaleas'. The remaining four subgenera contain very few species. The largest of these is subgenus "Rhododendron", containing nearly half of all known species and all of the lepidote species.