Scottish vascular plants in a global conext

Abstract

Summary A recent reassessment of the flora of Scotland has provided an estimate of 1000 native vascular plant species, excluding c. 350 microspecies in the genera Hieracium, Rubus and Taraxacum. The figure can only be approximate, as there are uncertainties about what constitutes a species and which accepted species are native. The total is lower than the equivalent totals for tropical or warm-temperate regions of similar area, and this almost certainly reflects the climatic differences between the regions as well as the recent glacial history of Scotland. The 50 oceanic species in Scotland are clearly important on a world scale; Scottish populations of species which are more widespread but currently declining in Europe may also be important but are difficult to identify in the absence of Europe-wide data on such floristic trends. Compared to other groups, the British ferns and fern-allies are extremely well represented in Scotland and flowering plants moderately well represented. The ferns include a large proportion of species in predominantly tropical genera. Scottish vascular plant species which are rare or scarce in Britain fall predominantly into the northern floristic elements. Of the eleven Scottish endemic vascular plant species currently recognised only Primula scotica appears to be manifestly distinct, thus calling into question the current very great emphasis on the conservation of endemic species.