Nowadays, there are 667 exotic species (PDF) referenced in continental Portugal*, which belong to 124 families, corresponding to approximately 18% of the native flora (Almeida & Freitas 2006, 2012). The great majority of the exotic species are Angiospermic (642 species, which represents 96,3% of the total); in a lower number there are the Gymnosperm’s, with 14 species (2,1% of the total) and the Pteridophyte’s with 11 species (summing 1,6% of the total). The most represented families are, in decreasing order: Asteraceae (Compositae) with 71 species, Fabaceae (Leguminosae) with 64 species, Poaceae (Gramineae) with 52 species, Solanaceae (29 species) and Rosaceae (28 species). * the authors include in this number the exotic species that are more or less naturalized. They don’t include many of the species that are found exclusively in gardens.
Almeida J, Freitas H (2012) Exotic flora of continental Portugal – A new assessment. Bocconea 24: 231-237.
Almeida JD, Freitas H (2006) Exotic naturalized flora of continental Portugal - A reassessment. Botanica Complutensis 30: 117-130.