Daphne caucasica I love this plant so deeply it is almost obscene, and for one simple reason: Fragrance. It is wonderful, and the kind of carrying fragrance that travels far. Customers smell while shopping for something else and have to take a moment to track down, and then have to have one. Better yet, flowering is pretty much continuous. Walk by the plants basically any day from May to October or even early November, and they'll have flowers on them, pumping out that exquisite perfume. Forms an upright shrub probably topping out around 3 feet. I consider it absolutely essential to happiness. Zone 5, at least.