This name is a synonym of Ulmus crassifolia Nutt..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50129522) with original publication details: Amer. Midl. Naturalist 27: 483 1942.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:259371-2.
This name was in version 1 of The Plant List, record tro-50129522, and has not been changed.