Plantain; this medicinal weed used world wide as food and treatment of many diseases. Its great fame stemmed ten centuries ago from its use as a treatment of wounds, when its anti-bleeding and anti-infection properties were discovered. In Egypt P. major has a wide rang of distribution specially in the Nile Delta. Growth pattern of P. major for several trends e.g. morphological traits, biomass allocation; environmental variables (soil); and biochemical analysis are evaluated in Damietta region. Quantification of floristic features; differences in phenotypic plasticity; and edaphic variables which affects the distribution and abundance of P. major was performed to stand on the ecological amplitude of P. major; its patterns of distribution; composition of its communities; role of its habitat characteristics on phenotypic plasticity and plant chemical composition besides the different factors affecting its seed germination.This book, provides data will be useful for credible management and cultivation of this medicinal weed.