Echinacea flower

I rarely see echinacea flowering although people tell me it’s commonly found in home gardens.
It’s a plant I value for its medicinal values.
I believe that it enhances the immune system and reduces many of the symptoms of colds and flu. I take it at the first hint of a sore throat. It works for me. I don’t know if it reacts with other herbal supplements though - it’d pay to be cautious.