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 Sable Island, Nova Scotia, Canada. J. Torrey Bot. Soc. 133: 362–374. 2006.—Sable Island, Nova Scotia, Canada, was surveyed for vascular plants in August 2002. The island's past and present flora comprises 61 families, 156 genera, and 224 species, of which 145 species (65%) are native and 79 species (35%) are non-native. The most species-rich families are Poaceae, Asteraceae, Cyperaceae, Polygonaceae, Caryophyllaceae, and Rosaceae. The largest genera are Juncus and Carex. Floristic studies of five earlier investigators are presented and discussed, including Macoun, conducted in 1899; Güssow, in 1911; St. John, in 1913; Erskine, in 1952; and Catling et al., in 1981. During the past 100 years, the island's flora has remained relatively stable; the number of native species has changed little and most plants introduced to the island have not become established.