Unshiu, not sure what the difference is other than clementine type mandarins are reticulata and satsumas are Unshiu. It's just the botanical name, what is your concern exactly? Here is a link to the CVC website with the description.

http://www.citrusvariety.ucr.edu/citrus/frostowari.html

Evan

Under the Tanaka classification system, Citrus unshiuis considered a separate species from the mandarin. Under the Swingle system, unshius are considered to be a group of mandarin varieties

For our our purposes it doesn't matter what it is only it's characteristics.

its a mandarin no matter how you cut it

Thanks. Just wanted to know the proper correct botanical name for it since I have a satsuma mandarin tree.

Nice job Pip, you put it much more eloquently than I did.