Plant identification is one of the hardest parts of herbalism. Having clear identification of any herb you use is critical. Many herbs have look-alikes that have harmful actions. Here are two herb look-alikes that have two completely different actions: purslane and spurge . Growing side-by-side, you can see how different they are. But growing individually, you can see how they can easily be confused. Another great tip to identify spurge, pluck a stem off and see if white sap (or milk) appears .