This name is a synonym of Salix laevigata Bebb.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50293501) with original publication details: Fl. Calif. 339 1909.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:225923-2.
This name was in version 1 of The Plant List, record tro-50293501.