Historical (mainly 1930s) and contemporary records of 482 vascular plant species or genera of non-littoral areas of 464 islands in the archipelago of SW Finland were compared, to visualise changes in distribution patterns, and to identify environmental variables that affect the distribution of the species. The environmental variables were measured in a GIS. Logistic regression analysis was used to find variables that affect the probability of species occurrences. Results, with distribution maps, are presented for each species. This seventh and final part of the series contains results of the family Poaceae and a synthesis of the whole study.