Cypress are deciduous trees with tiny feather-like leaves and small, scaled, ball-shaped fruit. Their tall, straight trunks are very wide at the base and slim at the crown. Cypress roots will grow up into distinctive rounded knobs called "knees," but only when the tree's root system is submerged in water.

Cypress trees are more tolerant to flooding than any other species of tree and, consequently, are commonly found in swamps and wetlands. They prefer a somewhat drier environment, and are surprisingly drought tolerant.

Cypress wood is dense and valued for its tolerance to water, especially the heartwood of the tree, and is used in many outdoor applications.