L. hybrida earns its name by being intermediate in appearance between fringed and lanceleaf loosestrife. Judging by descriptions, I long thought if I ever saw it, it would be hard to tell the difference between this and lanceleaf. The key depends on stem thickness, leaf shape, and nerves in the sepals, all variable traits. But when I saw this patch of plants in Apalachicola National Forest, I immediately knew it was something new and different. The overall appearance clearly sets it apart. Taller and bushier than lanceleaf, and clearly not fringed on the petioles. Kind of like lanceleaf on steroids, but the leaves are no bigger. Lowland yellow grows in AR, AZ, CT, DE, FL, GA, IA, IL, IN, KY, KS, MA, MD(T), ME, MI(X), MN, MO, MS, NC, ND, NE, NH, NJ, NM, NY(E), OR, PA(T), RI, SC, SD, TN, VA, VT, WA, WI, WV, AB, MB, ON, QC, and SK. Wakulla Co FL, 7/8/18.