Flandrian history of the Teesdale rarities

THE survival of the Teesdale rarities through the Flandrian period ¹, during the prominence of inimical conditions that led to the development of woodland and blanket peat and the podsolization of the soil, suggests either that the present habitats have provided similar conditions since the widespread distribution of the rarities in Late Glacial times² or that the habitats are of recent origin and the plants survived elsewhere ³. Neither of these hypotheses is based on the ecological history of Upper Teesdale but on a comparison of the present flora with that of Late Glacial times in other areas and on the assumption that the vegetational history of Upper Teesdale has followed a similar course to that of other floristically rich areas (for example, Ben Lawers⁴, Cwm Idwal⁵).