| At the subgeneric level, the classification of Valeriana in subgenera and sections is difficult. |
| Most of the traditionally recognized subgenera of Anchusa are also supported as monophyletic groups by both nuclear and plastid sequence data. |
| The most comprehensive monograph of the genus divides Rhynchospora into two subgenera and 29 sections. |
| The genus is about equally divided into two subgenera, those with pedicellate flowers and those with sessile flowers. |
| Nevertheless, several Lutzomyia species can transmit both, representatives of the Viannia and Leishmania subgenera. |
| Several genera that are at times segregated from Atriplex have been variously treated as subgenera or sections, or simply placed in synonymy with Atriplex. |
