Plant family: Cabombaceae
Water shield (Brasenia schreberi) is a small floating leaf plant compared to the water-lilies which it resembles. Its leaves are oblong with a length of 5-12 cm and a width of 2.5-6 cm. This aquatic plant grows commonly to about a depth of 2 meters, but sometimes deeper. It can form dense stands and provides great hiding places for bluegills and other panfish. I have often fished the edge of such beds on northern Wisconsin lakes with great success for bluegills and the occasional yellow perch.
Water-shield has a understated, but interesting brown-purple flower with pettals from 12-15 mm long, appearing in July. These flowers are easy to overlook as they blend in well with the many floating leaves.
Sometimes, water-shield leaves can be confused with young or small American lotus (Nelumbo lueta). However, the leaves of the lotus are circular and grow much larger, and the two species are not found in the same habitat.