The role of fibres and the hypodermis in Compositae melanin secretion

► We describe the cellular processes of the melanin secretion in Compositae fruits. ► The ultrastructure of hypodermal cells indicates protein/amino acids synthesis. ► Hypodermal cells are not responsible for the secretion of phytomelanin. ► The pericarpic fibres show the typical cells that secrete carbohydrates. ► Phytomelanin is secreted by fibres and deposited in spaces inner to the hypodermis.