Lake Quillwort

Lake quillwort, Isoetes lacustris, is an aquatic lycophyte, a fern ally of the family Isoetaceae, native to the cold, clear, nutrient-poor lakes of northern and montane Europe, where it grows fully submerged, rooted in sediment near the shore. Its quill-like leaves radiate from a small corm-like base, and along with other quillwort species it plays a distinctive ecological role by drawing carbon dioxide from the sediment rather than the surrounding water, a specialized carbon-fixing strategy unusual among aquatic plants.