I have a aged mimosa tree and have noticed some kind of moss growing on the trunk,would anyone know what type moss typically grows on these trees.
It is impossible to answer your question.
There are many epiphytic mosses.
Where are you located?
Got a photo of the moss?
Really need to see it to even venture a wild guess!
Could be lichen, too. I see a lot of lichen on the trunks of old mimosa trees.