In order to study the germination capacity of Cryptogramma crispa, spores were cul- tured on sterilized Petri dishes with nutritive medium solidified with agar. Germination was checked at 10, 15, 20 and 25?C, and, as in most of homosporous ferns, the germination optimum was at temperatures above 20?C. Two light intensities were used, 10 and 40 iLEm-2s-, to reproduce the possibilities of the spores falling on open sites or in rock cracks or hollows. A lower light intensity accelerates germination. After sowing, some plates were kept at chilling and other at freezing temperatures to check the effect of low storage temperatures on the germination capacity of the spores. After these processes, the spores are able to germinate and reach similar germination rates, although the frozen spores delay the beginning of germination and show a decreased ger- mination rate. The results of these experiments point toward the possibility that the spores of C. crispa are dispersed at the end of the growing season and go through a dormancy until next spring. In the Iberian Peninsula (Spain and Portugal), Cryptogramma crispa R. Br. grows on ecologically very particular and well defined habitats. It occupies especially siliceous stone fields, such as granite, gneiss, sandstones, quartzites, or slates in high mountain zones, usually above the timber-line. In the Iberian Peninsula, its optimum is about 2000 m. The plants grow preferentially in rock fissures or cracks and in hollows between rock blocks. In these habitats, which are mostly over 2000 m elevation, the growing season may be very short, scarcely two months in extreme conditions, and usually no more than four months (Rivas-Martinez, 1987). The considerations of the distribution of pteridophytes suggest the need for more detailed investigations on the life-cycles of species to determine the im- portance of specific variations in the life-cycle in limiting the distributions of plants. Variations in the distributions of species might be accounted for by random processes, such as dispersal, or in a more deterministic manner by subtle and specific variations in life cycle characteristics (Woodward, 1987). In ferns, it is important to study the factors that can affect the development of the gametophyte that would lead to the establishment of the sporophytic gen- eration.