I always found Tarragon a very interesting herb although I do not use it often in cooking. It has a lovely flavour but needs to be used fresh and added to the dish just before serving. It makes a lovely vinegar and finely chopped leaves can be added to butter and mixed in well before spreading onto warm toast. The plant was used in during the middle ages for treating scurvy due to its high vitamin C content. Research has shown that Tarragon can help stabilize blood pressure and the plant contains high levels of Rutin. NOTE: Tarragon was used to induce menstruation and hence should not be used during pregnancy.
In ancient times tarragon was used as an antidote against the venom of dragons, I cannot vouch for this as we rarely have dragons on our farm.