Hi, It is the leaves. Pick tender top leaves, wash thoroughly, lay on newspaper to dry. When completely dry, they can be kept in a tight container until needed. I use an infuser (tea ball) to brew. It takes very little to flavor a cup of tea. 3 or 4 leaves will do a whole pitcher. I have the wild variety for tea and it is much stronger than the plants you purchase at the nursery. Too much makes a very bitter tea.Hope this helps. Christine