Posted: 22/05/2015 at 16:26
I would suspect they are a protected plant and they are breaking the law by damaging them. They are certainly pretty uncommon.
It is possible to protect plants by putting down the metal bridges which farmers use to cross pipes carrying liquid muck to the fields? In my experience some plants are very specific as to where they will grow and if you move them they may be lost completely.
It may even protect them best if a metal plate is put over them, because at least the roots will still be there. It is sad though that plants can be destroyed so mindlessly and easily.