Keith; Cork Screw Willow. Salix matsudana "Tortuosa " Also known as Pekin Willow, Hankow Willow, Curly Willow, Twisted-Twig Willow. It is not native to North America, but can be found in all states except maybe Florida. Small to medium tree growing to 30' tall and 15' wide. Main feature is it's contorted and twisted branches. Winter branch pattern probaly accounts for the popularty of the tree. Will grow any place there is fresh water, and is a rapid grower. Jim S