The identity of the Aravos:
The Torah states that one is to take a Arvei Nachal. This refers to the willow branch.
The following are the signs of a Kosher Arava.
- A red stem: This means that the Arava comes from a tree that grows red stems. Thus even if the branch is currently still green due to lack of sunlight, nevertheless it is valid, as it will eventually become red due to the sun.
- The leaves are shaped like a brook; narrow and long.
- Leaves that have smooth edges, not serrated like a saw. If the leaves have tiny serrations they are still considered smooth edged. If however the serrations are large they are invalid.
The Arava must have all three signs to be Kosher. An Arava that has red stems and long narrow leaves, but has large serrations, is invalid.
Do Aravos have to grow by the water to be valid?
Although majority of Aravos grow near banks of water they are valid from all areas, even if they grow in a desert or mountain, being that they have all the signs.