Rowan or Sorbus aucuparia.
The Mountain Ash is Sorbus aucuparia. I know of no tree called the Rocky Mountain Ash.
Another name for the European mountain ash is the Rowan tree.
Fraxinus ornus
The scientific name is Acer negundo. I found this on http://www.wildflower.org/plants/result.php?id_plant=ACNE2
Fraxinus americana.
Rowan the Mountain Ash
The name would be Fraxinus excelsior.
Sorbus americana
Another name for the Rowan Tree is the Mountain Ash. It is known for its clusters of bright red berries and is often associated with various myths and folklore, particularly in Celtic traditions. The scientific name for the Rowan Tree is Sorbus aucuparia.
The name would be Fraxinus americana.
Fraxinus excelsior (European) Family: Oleaceae.
The scientific or taxonomic name would be Pristiphora geniculata.