Distribution and biological characteristics of threatened vascular plants in Finland

The Red Data Book of the threatened animal and plant taxa in Finland was published in 1986. In this present paper, we analyse the geographical distributions (in Finland and the Northern Hemisphere) and several biological characteristics of the 83 vascular plant taxa classified in the Red Data Book as Disappeared, Endangered or Vulnerable. We compared the biological characteristics of each threatened taxon with those of a taxonomically close, but more common, relative (if possible, from the same genus) in order to analyse why one is threatened and the other not. The majority of the threatened taxa in Finland seem to occur close to the limit of their climatically determined areas of distribution, where edaphic conditions also become increasingly important. Threatened taxa tend to begin flowering later than their common relatives in the Finnish flora.