As we suspected, more/detailed pix would be helpful but Michael has replied with this .....
" .......Not enough information to be absolutely certain. Firstly the naughty bits of the flowers must be showing to help with the ID., and then a very intimate close up of them would help.
I know only one Salix that fasciates frequently and that is Salix udensis 'Sekka' the Dragon-tail Willow and that is a male clone. Sekka does tend to be a sprawling bush as Mark mentions.
Ask Mark to check out my website
www.willowsvermont.com and look up Salix udensis 'Sekka' to see it my photos match his plant! The leaves are very distinguishable on udensis and are very attractive and the edges are rolled under making for a quick ID when in leaf!
I hope this helps.
Warmest regards
Michael "
Thank you, Michael!