Ti leaves from the ti plant were considered by ancient Hawaiians
to have divine power.  Native Hawaiians believe that growing ti
plants around a home can bring good luck.  The ti leaf has a
variety of uses, including foot coverings, hula skirts, plates,
food wrappers, and house thatching.  The root is also edible.  
One Hawaiian legend says that if a person worries that a body of
water contains a shark or supernatural creature, they may throw
in a ti leaf.  If it floats the water is safe, and if it sinks
the water is not safe.  Try to keep your tie dry and hope it
brings you luck.