The Genus Sorbus

European Mountain Ash, Rowan: Sorbus aucuparia -

Oakleaf Mountain Ash: Sorbus hybrida -

Cascade Mountain Ash, Rocky Mountain Mountain Ash, Greene's Mountain Ash: Sorbus scopulina var. scopulina (Synonym: Sorbus scopulina var. cascadensis) - Small tree to 12 feet. Flowers small, white, in round clusters like an overturned plate (cyme). Leaves compound pinnate, very shiny, with small serrations.

Gray's Mountain Ash, Sitka Mountain Ash, Western Mountain Ash: Sorbus sitchensis var. grayi (Synonyms: Pyrus occidentalis, Sorbus occidentalis) - Small tree to 12 feet. Flowers small, white, in round clusters like an overturned plate (cyme). Leaves compound pinnate, a dull blue-green, with small serrations.