One of the more unusual features of Clymer Meadow is a microtopography called “gilgai” by soil scientists and “hogwallows” by farmers. Normal gilgai are irregular or round, shallow basins, often arranged in a honeycomb-like pattern on level, heavy clay soils. Because they tend to hold water, they influence the composition of the plant communities. Moisture-loving species such as eastern gamagrass and prairie rose occupy the frequently inundated microlows, while drier-adapted species such as sideoats grama and little bluestem are common on microridges