Complex sentence: Plants, especially trees, continue to hold a complex and important interest for the Huaorani, whose store of botanical knowledge is extensive and ranges from knowledge of materials to poisons to hallucinogens to medicines.
Split into simpler sentences: Plants, especially trees, continue to hold a complex and important interest for the Huaorani. Their store of botanical knowledge is extensive and ranges from knowledge of materials to poisons to hallucinogens to medicines.