A Note on the Taxonomy and Cytology of Pyrrosia nummularifolia (Sw.) Ching and Pyrrosia obovata (Bl.) Ching

The discovery of great range of morphological intergrades between the orbicular sterile fronds o. very carnose texture with cordate or rounded base on stipes 1-2 mm. long, characteristic of Pyrrosia nummularifolia (Sw.) Ching and obovate or spathulate fronds of carnosopapyraceous texture with cuneate base on stipes 1-2 cm. long as assigned to Pyrrosia obovata (B1.) Ching, suggests that P. obovata should be merged in P. nummularifolia on the basis of the rule of priority and there is no justification whatsoever to assign the former even the status of a variety or forma of the latter species.

The cytological findings of n = 37 and 2n = 74 in Pyrrosia nummularifolia (Sw.) Ching from the Khasi Hills conform to one of the two basic chromosome numbers x = 36 and 37 discovered so far within the genus Pyrrosia.