Abstract :
Ophioglossum lusitanicum L. (Pteridophyta) is recorded from Iran. Based on morphological, anatomical, sporological and ecological investigations, it is possible to distinguish this species from the wellknown one in northern Iran, O. vulgatum L. Its discovery in a submountain area of Langerud, Gilan province, represents an extension of its phytogeographical range in eastern Eurasia. Geographical distribution and characteristic details of the species as well as a concrete comparison with O. vulgatum is presented.