The subfamily Dryadoideae consists of four genera in the family Rosaceae,[1] all of which contain representative species with root nodules that host the nitrogen-fixing bacterium Frankia.[2] They are subshrubs, shrubs, or small trees with a base chromosome number of 9, whose fruits are either an achene or an aggregate of achenes.[1]
The subfamily has at various times been separated as its own family (Dryadaceae), or as a tribe (Dryadeae) or subtribe (Dryadinae).[3]