Texas forest lands can be divided into six major regions: the Big Thicket, the Piney Woods, the Gulf Coast, the Edwards Plateau, the lower Rio Grande Valley, and the Trans-Pecos mountain forests. East Texas is home to the Piney Woods, a vast region extending from Texas through parts of Oklahoma, Arkansas, and Louisiana. These woodlands feature many varieties of pine as well as hardwood varieties including magnolia, American Sweetgum (Liquidambar styraciflua), and elms (Ulmus spp.). The Big Thicket is the southern portion of this region, and has historically been the most densely wooded part of the state, acting as a natural divide between Southeast Texas and coastal Louisiana. The Texas coastal region has more sparse tree growth but still contains many varieties including Southern Live Oak (Quercus virginiana), mesquite (Prosopis spp.), and Texas Persimmon (Diospyros texana). The Edwards Plateau region of Central Texas contains woodlands featuring Ashe Juniper (Juniperus ashei), Texas Live Oak (Quercus fusiformis), and Honey Mesquite (Prosopis glandulosa). The lower Rio Grande Valley has historically been home to a large semitropical forest of Mexican Palmetto (Sabal mexicana). Though West Texas is mostly grasslands and desert, mountainous areas in the Trans-Pecos portion, such as the Guadalupe Mountains, contain oases of forest lands featuring Bigtooth Maple (Acer grandidentatum), Velvet Ash (Fraxinus velutina), Grey Oak (Quercus grisea), and similar tree species.