Stalter, R. (Department of Biological Sciences, St. John's University, Jamaica, NY 11439) and E. E. Lamont (Honorary Research Associate, Institute of Systematic Botany, The New York Botanical Garden, Bronx, NY 10458). The historical and extant flora of Great Gull Island, New York. J. Torrey Bot. Soc. 132: 628–634. 2005.—Great Gull Island, Suffolk County, New York was surveyed for vascular plants in 2002. The island's past and present flora consists of 207 species, 148 genera, and 55 families; the largest families are the Asteraceae (35 spp.) and the Poaceae (34 spp.). Fifty seven percent (119 spp.) of the flora is not native. The greatest change in the flora since the 1970s has been the addition of 16 species of composites and 12 species of grasses. The island's long history of human impact is reviewed, especially the impacts upon the flora resulting from management of the island as a wildlife preserve for nesting birds. Significant changes in the island's flora and vegetation have occurred during the past two decades.