On the holiday of Sukkot, Jews around the world make a blessing on the four species; one with no taste or smell, one with both taste and smell, one with no smell but a taste and one with no taste, but a smell.
The best known of these are the Lulav and the Etrog. The Lulav is a tightly closed frond of the date palm tree. It has many layers which must come to a point at the top. If the point is blunted, then the branch is not usable for the purposes of fulfilling the commandment. It has taste, but no smell.
The Etrog, a citron, is a lemon-like fruit that has both taste and smell. Its skin may not be cut or damaged in any way. Its pitam or pitom, is a stigma which cannot be damaged. However, it may fall off naturally.
The Aravot are the leafy branch of the willow tree. It has neither taste nor smell. The Hadassim are branches of the myrtle tree. They have a smell, but no taste.
The four species are held together when making the blessing, usually, the blessing is made during the morning services just before the Tora reading of the day. However, one does not need a minyan, a quorum of ten to make the blessing, nor does one need to be in a synagogue.
People can be seen all over Israel throughout the week of Sukkot with a set of the four species, offering passers by the opportunity to make the blessing. The blessing is made each day, except for on the Shabbat, the Sabbath. This is due to a rabbinic decree banning it on Shabbat so that people would not come to commit prohibited acts on the Sabbath. The fear is that people may come to harvest the items on the Sabbath for use, which is one of the prohibited activities of the day.
Jewish law has strict rules over what constitutes a kosher Etrog, Lulav, Hadass or Aravah. There are many levels ranging from simply kosher to being of the highest purity and perfection. Sets of simply kosher four species can be had in Israel for as little as $10, or less if one waits to buy them just before the start of the holidays. The highest level ones can cost thousands.
TPS photographer Shalom Shalev took pictures of people examining the different species to determine their level of quality before purchase. The people can be seen at the “Shuk Arba Haminim” (the four species market) right next to the Mahane Yehuda market in central Jerusalem.