latter to declare the area as either reserved or within protected forests to allow the department to have stricter legal control. However, no such declaration was made. The park was further expanded to a total area of in 1981. In 1996, the park was renamed to its current title, Sanjay Gandhi National Park, after Sanjay Gandhi. The same year, some forests from the Thane division were merged into the park, further expanding its total area to . Geography The park occupies most of the northern suburbs of Mumbai. To the west lie the suburbs of Goregaon, Malad, Kandivali, Borivali and Dahisar. To the east lie the suburbs of Bhandup and Mulund. To the south lies the Aarey Milk Colony and the university campus of IIT Bombay. The northern reaches of this forest lie in Thane city. The park and the areas surrounding it, except Thane city, are all part of Mumbai. It is the only protected forest located within the limits of a city. The region is hilly with elevations between . The park has two lakes, Vihar Lake and Tulsi Lake, which meet a part of the city's water requirements. The park is said to be the lungs of the city as it purifies much of the air pollution in the city. Biodiversity The park is forestland, with an estimated 800 types of mauve. This flower is native to the park and the surrounding regions, including Karnala, the Yeoor hills, Tungareshwar, and some parts of Goregaon's Film City. The park is also home to a small population of leopards. Wildlife The park is home to a number of endangered species of flora and fauna. The forest area of the park houses over 1,000 plant species, 251 species of migratory, land, and water birds, 5,000 species of insects, and 40 species of mammals. In addition, the park also provides shelter to 38 species of reptiles, 9 species of amphibians, 150 species of butterflies, and a large variety of fish. Flora Kadamba, teak, karanj, shisham, and species of acacia, ziziphus, euphorbia, flame of the forest, red silk cotton tree, and a number of other varieties of flowers. Mass flowering of karvi The karvi (or karvy) shrub, as it is locally called in the Marathi language, only blooms once in eight years in a mass flowering covering the forest floor in a lavender blush. It grows in abundance in the Western Ghats