Salix prolixa MacKensie's willow

Information from USDA Plants Database 

http://plants.usda.gov/java/profile?symbol=sapr3

https://www.google.com/search?q=Salix+prolixa+MacKenzie's+willow&hl=en&source=lnms&tbm=isch&sa=X&ei=jQlLUfyeF4aZiALQ9IDwCQ&ved=0CAcQ_AUoAQ&biw=1008&bih=522