The flora of Scotland is an assemblage of native plant species including over 1,600 vascular plants, more than 1,500 lichens and nearly 1,000 bryophytes. The total number of vascular species is low by world standard but lichens and bryophytes are abundant and the latter form a population of global importance. Various populations of rare fern exist, although the impact of 19th century collectors threatened the existence of several species. The flora is generally typical of the north west European part of the Palearctic ecozone and prominent features of the Scottish flora include boreal Caledonian forest (much reduced from its natural extent), heather moorland and coastal machair. In addition to the native varieties of vascular plants there are numerous non-native introductions, now believed to make up some 43% of the species in the country.
There are a variety of important trees species and specimens; a Douglas Fir near Inverness is the tallest tree in the United Kingdom and the Fortingall Yew may be the oldest tree in Europe. The Shetland Mouse-ear and Scottish Primrose are endemic flowering plants and there are a variety of endemic mosses and lichens. Conservation of the natural environment is well developed and various organisations play an important role in the stewardship of the country's flora. Numerous references to the country's flora appear in folklore, song and poetry.