Problem with collecting plants

i made a little script that i attached to my 3d person camera but it wont work it only works with that 1 prefab plant in the scene or when i copy that plant from the scene all plants disappear at once help i cant figure it out :(

  var PlantPos :Transform; // The var will hold the pos of the camera
  var dist;                // the var will hold the distance between the 2 objects
  var Plant :GameObject;  // the var where the gameobject will be saved
 
 
 
  
 function Update () { // updates every frame;
 
  if (PlantPos)  {
  
  var dist = Vector3.Distance(PlantPos.position,transform.position);
  print ("Distance to the Plant:" + dist);
  
   if(dist<=3 && Input.GetKeyDown("e")) // if the distance is lower then 3 then the plant will get
                                        //deleted if the user presses e
 Destroy(Plant);                       //destroys the object
 
  
 
  
  
  }
  }