The species of subgenus "Ducampopinus" were regarded as intermediate between the other two subgenera. In contrast two clearly defined monophyletic clades emerged corresponding to the above two subgenera. These two subgenera are probably not monophyletic. The genus may be broadly divided into three subgenera. Various schemes have subdivided the genus into subgenera and sections. There are numerous distinct subgenera and subsections in this genus. These four subgenera were elevated to full genus status. This listed 165 taxa grouped into 6 subgenera, 130 species, 17 subspecies, and 9 varieties. He then further subdivided the genus into seven subgenera. The most recent classification of "Quercus" divides the genus into two subgenera and eight sections. There are 250 species split into 38 subgenera within the genus "Bombus". The small polyphyletic subgenera "Pentanthera" and "Azaleastrum" were divided between two clades. The genus includes some 500 bees in 31 subgenera. However the subgenera do not appear to be monophyletic. The "Trillium" genus has traditionally been divided into two subgenera, "T." subg.