The archipelago of Cape Verde consists of nine main islands of oceanic origin situated 500 km west of the African mainland. The present study aims at increasing our knowledge of the endemic vascular flora and its origin and evolution, and at providing a scientific basis for its protection. One endemic genus (Tornabenea)and 82 endemic species and subspecies were accepted, including one new species in Tornabenea (T. humilis)and three new combinations in Campylanthusand Kickxia.Morphological descriptions, illustrations, typifications, chromosome numbers, phyto- and ecogeographic information, and conservation status, based on field-, herbarium-, garden-, and literary studies, are provided. The degree of endemism was 10.5% at the species level. The endemic flora had a mixture of holarctic (65%, including I 5% in a NW-Moroccan element) and tropic (35%) affinities. Thirty-three Capeverdean endemics ( 40%) were most closely related to taxa with a Canaro-Madeiran distribution. The endemic flora was divided into five distributional elements (northern, western, southern, eastern, and ubiquitous; with 26, 21, I 5, 3, and 17 taxa. respectively) and three ecological elements (hygrophytic, mesophytic, and xerophytic; with 31, 34, and I 7 taxa, respectively). Although distributional patterns corresponded closely to geographic positions of island groups, the patterns could be sufficiently explained by ecological factors. Endemic species richness was strongly correlated with humidity and maximum island altitude. The tropic proportion decreased with increasing altitude and humidity. More than half of the endemic flora is presently threatened (Red List taxa), and 16 single-island extinctions were recorded.