Ulmus × hollandica and Ulmus × vegeta both share the same hybrid formula.
Ulmus × hollandica has been described in 1768 and is the valid name for this hybrid. POWO lists 99 different synonymes for this often cultivated hybrid between Ulmus glabra and Ulmus minor:
Another reason for this taxon merge is that both input taxa lack a space between the "×" and the epithet. POWO should be followed consistently here, it also serves to improve readability.
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
