Clove,
Deer's-tongue,
Nettle,
Rue, Slippery elm, and
Snapdragon.
Magickal suggestions for stopping bad rumors:
If bad things are floating around about you behind your back (or about others and you don't think they're very nice), try this. Try and get some whole cloves (they can be expensive, though), and either put them in a sachet or string them together. Stringing works best since it can be concealed. When alone in the workplace, school, or other place where gossip happens, place clove string or small clove bundle over doorway, where it will not be seen on the doorframe. Then trace the doorway's perimeter with your finger, exuding protective energy and trying to create a field, held by the cloves, to stop people from having those impulses to gossip once they pass by these doors.
-OR-
If it is a particular person that is spreading the bad rumors, drop a clove into his or her purse, backpack, or tote when unattended, or place in a desk or workplace. The clove should be charged with positivity, and cause a guilty feeling when a person utters damaging statements. If you yourself are trying to stop gossipping, carry the pouch of cloves yourself and just bite your tongue, telling the rumor to the package of cloves or writing it down later to avoid spreading it.
-OR-
If you work in an office where everyone (or one particular person) seems to gossip around you, see if you can get some potted snapdragon flowers. Keep them with you at work at your desk--this isn't really practical for school or active jobs, but at a desk job it works. Now, when you hear a rumor from someone, simply stare at the person as they say it and imagine the words floating through the air and being gobbled by your snapdragon plant. As you stare, do not show signs of amusement. The person will at least understand that repeating gossip to you is not a good idea, and may reconsider his/her actions when talking to others.