Cedar Bog is the largest and best calcareous bog or fen in Ohio. One of the most characteristic plants of this preserve is white cedar or arbor-vitae. Significant boreal, as well as prairie and coastal plain species, occur here.

Some of the more unusual plants include small yellow and show lady's-slipper orchids, smaller fringed gentian, swamp birch, shrubby cinquefoil, prairie valerian, Riddell's goldenrod and queen-of-the-prairie.