Any reason not to commit these?

Judging by this article by Yulia A. Kuzovkina and Irina V. Belyaeva http://salix.uconn.edu/NameChanges_14_113269395.pdf on whose work I think POWO has based it's naming of these Willows, I'm not sure that they mean these names are synonyms of S. gmelinii

"Interestingly, S. dasyclados was often treated as a hybrid (written as S. ×dasyclados) in some European references (for example, in Rechinger (1964), Newsholme (1992)),because it resembles some hybrids of S. viminalis. These hybrids, in which the second parent is a species from the section Vetrix (such as S. caprea L., S. atrocinerea Brot.), were commonly cultivated in Western Europe under numerous names: S. stipularisSm., S. smithianaWilld., S. calodendronWimm., S. acuminataSm., S. longifolia"