This book by authors thoroughly experienced in the ferns of Pakistan and of the Swat region catalogues and illustrates the 105 species (and additional subspecies) of pteridophytes currently known from greater Swat (Swat, Shangla and Buner Districts) in the far northwestern part of Pakistan. This area is within the Flora Iranica delineated region, west of the Indus River, but is not as well-known as other districts of the country as no fern collections were made there until as late as 1938, and collecting only began in earnest with the work of the late Dr R.R. Stewart in 1952.
As a result of studying all collections from there, including modern ones, the authors reveal various surprising westward extensions of species, even though the fern flora is much reduced compared to more easterly parts of northern Pakistan. Their study has also revealed a higher proportion of European versus Sino-Himalayan species in this far western part of the Himalayas.
Details of previous collectors are followed by a species list with brief descriptions, basic synonymy, and misapplied names, along with lists of specimens identified by the first author. Because recent pteridological work in Pakistan has involved large-scale misidentification, misreporting of exotic species, and failure to take note of identifications made by the first author in Pakistani herbaria, the book is intended to kick-start more serious and accurate work on the Pakistan fern flora. A list of the large number of highly mistaken and exotic taxa reported in recent papers concludes the work in an effort to help local workers avoid such mistakes in the future.