Ulmus serotina, also known as September elm or late-leafing elm, is a native North American deciduous tree that is commonly grown for its attractive foliage and shape. The tree is known by many other names, including red elm, rock elm, and sweet elm. The term "red elm" refers to the reddish-brown color of the wood, while "rock elm" is used because of the tree's strength. The name "sweet elm" comes from the tree's inner bark, which is sweet and has been used by Native Americans for medicinal purposes. Regardless of what it is called, Ulmus serotina is a beautiful tree that will add value to any landscape.