Although ferns were not included in Trimen's original five-volume 'A Handbook to the Flora of Ceylon', they form a significant part of the vascular flora of the island. A good deal of fern research was carried out contemporaneously to, but independently of Trimen's work. Publications, though, were widely scattered throughout the literature or constituted major works in their own right, i.e. that of R.H. Beddome 1863-1883. Therefore, an additional volume, in the new work 'A Revised Handbook to the Flora of Ceylon', was published in order to provide an accessible taxonomic base for studies on this element of Sri Lankan vegetation.