Southern yellow pine (often abbreviated SYP) doesn’t refer to any one species of tree, but rather a group of three-needle pine species which are classified as yellow pine (as opposed to white pine), and are native to the Southern United States. They grow very well in the acidic red clay soil found in most of the region. The species include Loblolly, longleaf, shortleaf, and slash pines. It typically has a density value between 50–55 lbs/cubic foot when pressure treated.