Biodiversity of Horticultural Crops-their conservation, documentation, characterization, morphological and molecular description, bioprospecting and studies on uses and product development- are assuming considerable significance. Biodiversity is even described as wealth of nation and even linked to wellness and happiness of man and fitness of planet earth as his abode. Climate change, natural disasters like flood, drought, earthquakes and hurricanes and above all " greed of man" are shrinking the biodiversity spectrum. Number of plants in red data book is on rise and plants getting extinct are increasing- recorded and unknown-. There is limited interest in the profession of taxonomy. Recent legislative measures - Biodiversity Act, Plant Variety Protection and Farmers Right Act and Geographical Indication and Intellectual Property Act- would reveal the commitment of Government of India to the conservation of biodiversity. Plants are worshipped and they were conserved in sacred groves, heritage sites, plant parks and botanical gardens. The mangroves near coastal areas are places of co-existence of plants and fauna. The present Volume IV BIODIVERSITY OF HORTICULTURAL CROPS is a continuation of earlier volumes with emphasis on sacred groves and heritage sites. A few underexploited crops are also covered. The contributors are eminent working scientists who have spend their lifetime in research and teaching of biodiversity of horticultural crops. The recent organizational structures like Biodiversity Management Committee, State Biodiversity Athority and National Biodiversity Athourity would facilitate attaining the mission of Convention on Biodiversity of United Nations.