Yearly, During The Feast of Tabernacles there are
7 Days of God's "Daily" afternoon Feast March
with all Members holding up the 4 species:
 
Which are an:
1.) Etrog (also known as the Citron) = the fruit of the goodly Tree of Life : and "Representing" holding up your Heart to God,
in one hand;
 
and in the other hand,
Three Species of Branches:
2.) The Palm branch (known as the Lulav) represents your spine;
3.) The Myrtle branch (known as the hadas) represent your eyes;
4.) The Willow branch (known as the aravah) represent your lips and your mouth.
In waving all elements together above you, and reciting your praises to The Lord during the March, we indicate that we are serving God and
expressing our gratitude, with every fiber of our being in a:
March of Joy!
Again: The four species are: 
Etrog - citron (a citrus fruit native to Israel) 
Lulav - palm branch 
Hadas - myrtle branch 
Arava - willow branch
The etrog is held separately. The three branches are bound together and referred to 
collectively as the lulav.

Rejoicing with the Four Species

With these four species in hand, recite a blessing and wave the species in six 
directions (east, south, west, north, up and down) to symbolize that God is 
everywhere. 

The four species are also held during the Hallel prayer. 

Each day during Sukkot, there are special processions. The etrog and lulav are held 
during these processions. These processions, called hoshanas because during the 
procession a prayer with the refrain hoshana (please save us) is recited, commemorate 
similar processions around the altar of the ancient Temple in Jerusalem.