Thorn forest once blanketed the Rio Grande Valley. Restoring even a little of it could help the region cope with the impacts ...

but the trees are prone to spreading aggressively and are covered in thorns. Native to the south-central part of the United States, Osage-oranges aren't actually oranges at all but are instead in ...

View the most popular Photo of the Day images from 2011, featuring Namibian thorn trees, a whitetip shark and diver in the Bahamas, a birch-covered boulder in the Adirondacks, Dubai skyscrapers ...