'Morden's Gleam' is a seedless, non-invasive Loosestrife (Lythrum virgatum). It grows to 3 feet tall and in July and August bears beautiful tall spikes of pinkish-purple flowers prized for the beauty of their reflection on water. Its cousin, Purple Loosestrife, is banned in many states, including Missouri, because a single plant produces as many as 2 million seeds, making it highly invasive and destructive in wetlands. Not to worry about this one, though. It's safe and legal. In the Ozarks, it's also a perennial.