Dryadoideae
The Dryadoideae subfamily of the Rosaceae consists of four genera, all of which contain representative species with root nodules that host the nitrogen-fixing bacterium Frankia. 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.The subfamily has at various times been separated as its own family, or as a tribe or subtribe.
