A floristic inventory of the remnant pinelands of the U.S.D.A. Subtropical Horticultural Research Station at Chapman Field, Miami-Dade County, Florida was conducted from July 2002 to March 2003. From the two-hectare study site, 159 vascular plant species were documented. These included six ferns and fern allies, two conifers, and 151 angiosperms (representing 49 families and 124 genera). Of the 159 species, 118 are native to North America north of Mexico and 41 are non-native but naturalized. The families with the most species in the study area included Fabaceae (25 spp.), Poaceae (20 spp.), Asteraceae (15 spp.), and Euphorbiaceae (9 spp.). The best-represented genera were Chamaesyce (five spp.), Sida (four spp.), and five genera with three species each: Chamaecrista, Ipomoea, Lantana, Rhynchosia, and Senna. Five species are new records for Miami-Dade County. Ten Florida endemic species, eight Florida threatened species, four Florida endangered species, and one federally listed endangered species were documented.