Four types of vegetation are "taken" every day of the holiday of Sukkot. They are: lulav (palm frond), etrog (citron), hadasim (myrtles), and aravot (willows)
For the adventuresome folks who wish to venture into the uncharted waters of the Four Kinds market, here are some basic guidelines and tips that, when followed, will allow you to be a relatively knowledgeable consumer.