Some 200 cultivars exist, with early and late maturing forms suited to warmer and cooler climates, respectively, although mainly eight cultivars are used for commerce in China. They are also grown as an ornamental tree, as well as for their fruit. The most common way of propagating lychee is through a method called air layering or marcotting. Air-layers, or marcotts, are made by cutting a branch of a mature tree, covering the cut with a rooting medium, such as peat or sphagnum moss, then wrapping the medium with polyethylene film and allowing the cut to root. Once significant rooting has occurred, the marcott is cut from the branch and potted.