Phytomelanin is a dark-brown to black, highly resistant amorphous layer, found in the pericarp of mature cypsela of Heliantheae alliance (Asteraceae). It is a non-cellular organic mass, formed after fertilization as an extra cellular deposition in the schizogenous space between the hypodermal and fibre zones in the pericarp wall. It is an important taxonomic character which has been used in the tribal and sub tribal classification in Asteraceae. The phytomelanin is suggested to be a product deposited either from the hypodermis or epidermis which lie above the layer or from the cells of fibre zone lying inner to it. The different taxa of the Heliantheae alliance exhibit surface ornamentation due to the variation in the deposition pattern of phytomelanin. These variations are noticeable in the form of spines,
pegs and striations.