Willows are often pioneer species and important in conservation, soon colonizing disturbed habitats. Salicin, a compound of aspirin, occurs in the bark, and extracts from WIllow trees were used by indigenous people to treat toothache, gastrointestinal problems, and dandruff. Twigs were woven into baskets and split branches were woven into watertight containers, scoops, and fish traps. Slender straight stems were used for arrow shafts.