FLORISTIC DIVERSITY AND CHOROTYPE ANALYSIS OF THE PTERIDOPHYTES OF PAKISTAN

In the current investigation an attempt has been made to document the floristic diversity, chorotype analysis and occurrence of the Pteridophytes of Pakistan. Previously published literature was consulted in order to confirm the nomenclature, precise locations and other attributes of this unique group of plants. Many field trips were undertaken in various districts of Khyber Pakhtunkhwa and specimens of various herbaria were studied in Pakistan and from other countries. Our updated list of taxa confirms that there are 168 taxa belong to 45 genera and 19 families. Pteridaceace and Dryopteridaceae are found to be largest families with 35 taxa each (41.67%), followed by Aspleniaceae with 28 taxa (16.67%) and Athyriaceae with 24 taxa (14.28%). Asplenium is the largest genus with 28 taxa (16.67%), followed by Dryopteris with 17 taxa (10.12%) and Polystichum with 15 taxa (8.93%). Phytogeographically the Sino-Himalayan elements is the major component of the diversity of the pteridophye flora with 94 taxa (55.95%), 18 taxa (10.71%) are cosmopolitan and European elements have 13 taxa (7.74%). We found that 43 taxa (25.6%) are extremely rare, 39 taxa (23.21%) are infrequent and 37 taxa (22.02%) are common. Key words: Diversity, Flora, Habitat, Nomenclature, Pakistan, Pteridophytes.