Dryadoideae | |
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Dryas × suendermannii | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Rosales |
Family: | Rosaceae |
Subfamily: | Dryadoideae (Lam. & DC.) Sweet |
Genera | |
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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] It includes five genera (Dryas, Cercocarpus, Chamaebatia, Cowania, and Purshia), all of which except the first only occur in North America.