1. a layer of cells in woody plants that produces cork tissue
Usage: botanical

Examples

• The phellogen is responsible for the formation of the outer bark in trees.
• Cork oak trees have a particularly active phellogen that produces commercial cork.
• The phellogen develops as part of the plant’s secondary growth process.
• Botanists study the phellogen to understand how trees form protective bark layers.
• The phellogen produces cork cells that help protect the tree from environmental damage.
• In older tree stems, the phellogen replaces the epidermis as the protective outer layer.