Bill's issue on this tree is not out yet, so I don't know what he has, but
this is what I got when I asked the RHS for the correct name.

The taxonomy of elms is notoriously difficult and it is hard to find two
authorities who agree with one another.* Ulmus x hollandica is believed to be a
hybrid between U. glabra and U. minor, but there may be elements of U. plotii in
its ancestry too.* U. x elegantissima is thought to be a hybrid between U.
glabra and U. plotii.* 'Jacqueline Hillier' was discovered in a garden in
Birmingham, within the natural range of U. plotii, but its parentage is not known
for certain.* On account of the difficulty in determining parentage of hybrid
elms we take a broad view of U. x hollandica to include cultivars which might
have U. plotii in their ancestry.Unfortunately, until more definitive research
is carried out on the taxonomy of hybrid elms, the nomenclature will remain
confused.

All I can add is that it appears to be a tough little plant.
Iris

************************************************** ******************************
++++Sponsored, in part, by John Quinn++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++