Let's rather discuss the desirability of including Celtis in the
Cannabaceae

Iris Cohen schreef
The older authorities, including IPNI (IK) include Celtis in the Ulmaceae,
which belongs to the order Urticales. When did the above happen, & what is
the rationale?

+ + +
There is a difference in IPNI between IK which uses the original name of the
family and Harvard which assigns it to a family of their own choosing.

Actually it did not happen, but it is one of those things which could happen
any moment, just like we lost Araliaceae, Flacourtiaceae and Epacridaceae,
etc. If it does happen it may not hold, like Araliaceae which popped back up
after having been deleted.

Still it feels pretty weird losing Celtis from Ulmaceae, and even weirder to
see it assigned to Cannabaceae.
PvR