Dryadoideae

The Dryadoideae subfamily of the Rosaceae consists of four genera.^[1] These genera are unusual in the family Rosaceae because they all have the nitrogen-fixing bacteria called Frankia in their roots.^[2] Dryadoideae plants are subshrubs, shrubs, or small trees. Their fruits are either an achene or an aggregate of achenes.^[1]

Dryadoideae
Dryas × suendermannii
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Rosales
Family:	Rosaceae
Subfamily:	Dryadoideae (Lam. & DC.) Sweet
Genera
Cercocarpus Kunth Chamaebatia Benth. Dryas L. Purshia DC. ex Poir. (including Cowania)