Isoetes hieroglyphica is a species of quillwort in the Isoetaceae family. It can be found in lakes of Quebec, New Brunswick, Maine, and Wisconsin, though relatively few of these species have been found and the distribution is poorly understood. It bears 7 to 15 leaves, each 5 to 11 centimeters long. Sporangium can be 5 millimeters long and 3 millimeters wide, covered about one third by the velum. White, spherical megaspores are 580 to 700 micrometers in diameter, their rounded ridges forming a network. The relatively smooth kidney-shaped microspores are 37 to 45 micrometers long.