I'm suddenly interested in willow trees. From Reasons to be Cheerful: The beauty of lining a river with willow.
In the Stone Age, Neolithic folks used willow branches and mud to build roundhouses for their families. Jump forward several thousand years and European farmers were fashioning panels of stitched willow, called hurdles, to fence their farms or screen their gardens. Meanwhile, Native Americans constructed frames of black willow stakes and branches for the sweat lodges where their spirits were purified.
Today, dozens of species of willow are fitting into the toolkits of ecologists and conservationists, who find these trees fine specimens for preventing the decimation of the Ohio River Basin. By incorporating willow, their aim is to minimize erosion while keeping its seven major tributaries as free of pollutants as possible.