This name is a synonym of Salix caprea f. elongata (Nakai) Kitag..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 28301707) with original publication details: Fl. Sylv. Kor. 18: 135, t. 27 1930.
This name was in version 1 of The Plant List, record tro-28301707, and has not been changed.