These large trees are typically found alongside bodies of water or in the floodplain forest. There are 18 different species of willow native to Minnesota, ranging from small shrubs to large trees, but the differentiation between them is very difficult. Characteristics shared by all willows are narrow, alternate leaves ranging usually 2-6 inches, bark with coarse ridges and small seeds surrounded by white fibers attached to 3-4 inch-long catkin.