Purple Coneflower or Echinacea purpurea is one of the most popular perennials in the garden. In addition to being beautiful the flowers can also be used to make an extremely popular herbal tea, purported to help strengthen the immune system. With stems that can reach as high as 5 feet tall and beautiful, long-lasting purple flowers that are visible from afar, it is easy to see why every gardener should want them in their garden or meadow.