Book 24, Question 73
Why do prairie grasses have roots deeper than the plants are tall?
Prairie grasses like big bluestem can have roots reaching 10 feet or more underground, while the tops reach only 6 feet or so. Deep roots find water during dry spells, and they hold soil in the wind. If fire or grazing eats the leaves, the grass regrows from its roots. Most of the plant is underground, safe and ready to grow again.