Wheat. Explain the riddle. The riddle "When I was young, I was as green as a weed" describes the appearance of wheat at seedling stage, and "When I was old, I put on gold jewelry" refers to the fact that when wheat is ripe, the grains on the ears of wheat look like gold jewelry. The following "jewelry is cherished by everyone" means that wheat grain is a cherished food source, while the last sentence "no one in the world disobeys" means that wheat is an important food widely planted and eaten in the world.