Would appreciate your help in IDing this shoreline plant. I’ve looked in Welby Smith’s Sedges and Rushes of MN, an aquatic plant guide from Extension, various websites, etc. I’m probably staring right at it on the page, but not seeing it! It’s 3.5-4 feet tall, leaves are about 7/16” wide at their widest point, with a deep channel running down the center. Rough, almost sharp along edges. I’ve not seen any sign of flowering or inflorescence when I’m here in late July-Oct, and nothing like that spent from earlier. It grows right to water’s edge in very wet sand, but not in the lake. Spreads rapidly with below-ground fleshy runners/rhizomes, which can be seen poking through the sand in the photo of the base of the plants. It doesn't seem to be browsed by anything. If you need more info or photos, please let me know. Thank you for providing this service!