Arba’at Haminim (Arba'a Minim): A central rite of Sukkot, as commanded in the Torah (Bible), to hold together, bless and wave four kinds of plants. ”פרי עץ הדר, כפת תמרים, וענף עץ עבות וערבי נחל” These are traditionally known as Esrog, Lulav, Hadas and Arava.
Esrog : The esrog or etrog, citrus medica in English, resembles a lemon. It is considered the most splendid specie of the four and therefore tends to be the most expensive. Jewish people are always seeking the most perfect esrog, one having no blemishes. Many people never compromise, even if it is very expensive.
Lulav: The lulav, date palm frond in English, is the tallest, most prominent specie of the four. It has a spine in the middle that appears as a pale white stripe. The spine has double leaves at each of its sides. The center midpoint is called the “middle tiyomet” or just “tiyomet”. The tiyomet should be closed so you cannot discern that it is actually two leaves. The more tightly closed the tiyomet, the more prized the lulav.
Hadas: Hadas, myrtle branch in English, is a bush with a pleasant fragrance. Its leaves grow in groups of three. Three myrtle branches are bound together with the lulav. In large markets, like those in Jerusalem or B’nai Brak, you might see religious Jews using magnifying glasses searching for the best hadas branches where on every level the three leaves grow from the same point.
Arava: The arava, willow branch in English, has no smell or taste. Two willow branches are bound together with the lulav. Willow leaves dry out quickly, so it is recommended that care be taken to keep the leaves moist. Some people buy extra branches to replace their aravot during the festival.
Koishalach: The purpose of the koishalach (woven basket or holder) is to bind the three leafy species (lulav, hadas and arava) together. It is a “V” shaped holder with compartments for the Hadas on the right, the Lulav in the middle and the Arava on the left. It is made from woven dried strips of palm fronds since there aren’t a wide variety of materials suitable for holding these species together.