Botany, a plant that grows in geloid soils that have a crystalloid content of between 0.2 and 0.5 parts per thousand: Mr. Tree asked his students to find out which types of gelicole species of vegetation thrive in gelisol, a kind of soil that is found in cold climates.

Geloid soil is characterized by low salt content, weak solutions, strong colloidal properties and a crystalloid content of less than 0.5 parts per thousand.