Rhubarb pie is a pie with a rhubarb filling. Popular in the UK, where rhubarb has been cultivated since the 1600s, its introduction to Europe from China is attributed to Marco Polo. Besides diced rhubarb, it almost always contains a large amount of sugar to balance the intense tartness of the plant. A strawberry rhubarb pie, is a type of tart and sweet pie made with a strawberry and rhubarb filling. Sometimes tapioca is also used. The pie is usually prepared with a bottom pie crust and a variety of styles of upper crust. In the United States, often a lattice-style upper crust is used. This pie is a traditional dessert in the northeastern United States but is little known outside that region in the US. It is part of New England cuisine. Rhubarb pies and desserts are popular in Canada as well, as the rhubarb plant can survive in cold weather climates.