It is the five sprigs of aravot (willows) that are taken specificly for
Hoshanah Raba that are tossed on top of the Ark.
Ideas for the lulav:
1. Hang in on the wall or door -- nice.
2. Use it as tinder for burning the chametz -- going from one mitzvah to
3. Use it as part of a dry floral arrangement -- mine is sitting in one