At the risk of being provocative I would ask why on earth you would want to wear a plant badge? It’s a practice virtually unknown in Scotland and (now here’s the provocative bit) has no historical basis as s way of identifying friend from foe. This tradition is part of the C19th historical revival. I’m not saying that clans might not have had plant emblems, these probably date back to a proto-Celtic period, but they certainly could not have been worn as some form of identification.