what is an etrog

An etrog is a yellow citron or Citrus medica used by Jews during the week-long holiday of Sukkot as one of the four species. Together with the lulav, hadass, and aravah, the etrog is taken in hand and held or waved during specific portions of the holiday prayers. The etrog is a medium-sized citrus fruit, with a color, scent, and taste similar to a lemon. It is oblong-shaped, four to six inches long, and has a bumpy rind. The Yemenite variety of etrog is larger but looks quite similar. The etrog tree is an evergreen, which means its leaves should be green year-round. During Sukkot, the etrog must be perfect in stem and body and is generally placed in an ornate receptacle. The etrog is held in the left hand while the palm branch, with myrtle and willow entwined, is held in the right during rituals. On the seventh day of Sukkot, the four species are carried seven times around the synagogue.