A total of 2277 species of vascular plant in 868 genera and 158 families are recorded as native to the Republic of Singapore. This flora consists of 174 pteridophytes (7.6% of the total), eight gymnosperms (0.4%), 590 monocots (25.9%) and 1505 dicots (66.1%). Median values of species per family, genera per family and species per genus are 5, 2 and 1, respectively. The most abundant 'families' and genera in terms of species are Orchidaceae (196 spp.), Pteridophyta (174 spp.), Rubiaceae (140 spp.), Euphorbiaceae (116 spp.), Gramineae (100 spp.) and Eugenia (46 spp.), Ficus (43 spp.), Dendrobium (33 spp.), Bulbophyllum (29 spp.) and Cyperus (29 spp.). Trees constitute 37.2% of the flora, shrubs 9.8%, herbs 25.9%, climbers 14.0% and epiphytes 13%. Euphorbiaceae and Rubiaceae dominate the woody flora; pteridophytes, Gramineae and Cyperaceae the herbs; Rubiaceae, Palmae and Annonaceae the climbers and Orchidaceae and pteridophytes the epiphytes. Species confined to coastal habitats comprise 11.1% of the total flora; 73.5% are lowland forest species and the remaining 15.5% are non-tree species of open and frequently-disturbed sites. The vascular plant of flora of Bukit Timah Nature Reserve, the largest remaining patch of primary rain forest in Singapore, is also analysed. Its flora is similar to that of the forest component of the complete Singapore flora. The Singapore flora, in comparison with other tropical floras, is highly diverse, but appears depauperate in epiphytes and climbers.