ARGUABLY the world’s weirdest plant, Welwitschia mirabilis is a tangled mass of shredded, fraying leaves in the Namib desert. For a thousand years, perhaps more, it grows just two long leaves, which ...

Trees are typically organized into two categories: hardwoods (angiosperms) and softwoods (gymnosperms). A new study suggests that there is a third type of wood—known as “midwood”—that could explain ...