Fox Glove (Digitalis purpurea) was the source of medicinal digitalis. It is still a very useful cardiac drug but now produced synthetically. Before someone objects to not staying with the "organic" source, let me assure you that too much digitalis is very toxic and can cause fatal cardiac arrhythmia. The toxicity level is barely above the effective level of this drug. The amount of active chemical in the Fox Glove leaves is highly variable (how much sun, how much water, time of year it was harvested, etc.), so making Fox Glove tea was often associated with serious poisonings. Fortunately, handling plant parts is not an issue.