Distribution and ecology ofCystopteris (Athyriaceae) species within the Flora Iranica region

The distribution ofCystopteris fragilis andC. dickieana in Afghanistan within the Flora Iranica region is studied. The latter species, for some ecological reason, occurs more frequently at higher altitudes. In both taxa higher polyploid levels also occur at high altitudes. The phenomenon can be correlated with the boreal-arctic distribution pattern. Polyploidism and spore-size classes are briefly mentioned as well as possible ecological adaptations. Evolutionary differentiation within both taxa are complex and still unknown.Dedicated to Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday and in recalling historical trips to the marvellous Afghan flora and vegetation.