20. Stratification
The following rhyme is a good way to distinguish between the major plant types found in the prairie and wetlands. Sedges, which have a triangular base, are found on the transition zone between wetlands and prairie, rushes are found in the wetlands, and grasses are found on the dry prairie.
"Sedges have edges..." "Rushes are round..." "Grasses have joints and grow from the ground."
