Teesdale is one of the best areas in Britain for rare, wild plants. Most of the rarest species are arctic or alpine species, but the unique plant assemblage here includes 'southern' species at the northern limit of their range. Several of the rarest species grow in 'the unusual 'sugar limestone' habitat on Widdybank and Cronkley Fells, but other areas in the valley (especially the riverbanks and the high fell tops) support rare species. We are recording about 100 of these special plants in detail. And we are looking out for places where any of these species would benefit from changes in land management.