About 5 years ago I bought this plant from a nursery in Vermont, Melittis melissophyllum, not having a clue as to what to expect with this unfamiliar item. It has flowered reliably each year, and I find it a delightful aromatic plant with showy over-sized white mint blooms. It is a member of the mint family or Lamiaceae. I haven't bothered to learn more about this plant until I googled it today. Apparently is is a widespread and highly variable European plant, found all the way to Turkey. My plant appears to be an "alba" form, as most forms have a pink lip, and some are dramatically colored near red, such as in the cultivar Melittis melissophyllum 'Royal Velvet Distinction':
Doing a google image search reveals considerable variation... now I want to grow more forms of this plant.