The name would be Fraxinus excelsior.
Fraxinus excelsior (European) Family: Oleaceae.
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
The Mountain Ash is Sorbus aucuparia. I know of no tree called the Rocky Mountain Ash.
Fraxinus americana.
Sorbus americana
The name would be Fraxinus americana.
Rowan or Sorbus aucuparia.
It depends on the species but beech trees are members of the genus Fagus. For instance, the American beech is Fagus grandifolia.
carbon
The accepted scientific name is Podosesia syringae.