- from Trees
Trees have evolved to tower over other plants. To get so big, they need some special features. Unlike small plants with flexible stems, trees are “woody.”
As a tree grows from a seedling into a sapling, it develops a trunk and branches with stiff, woody cells at the center. The wood in the trunk and branches holds up the tree and provides structure, like the steel frame of a building. A young tree also soon grows an outer coat of hard, waterproof bark. The bark is its armor, protecting the tree from all kinds of weather and from being eaten by animals. Together, the wood and bark make trees so tough that some species can live for hundreds, even thousands, of years.