Abstract: Adiantum capillus-veneris L., commonly regarded as a good experimental plant for the study of fern development, is investigated, and its life cycle under laboratory conditions is described. In our study, the life cycle of A. capillus-veneris was completed in 100 days. Features of spore germination, antheridium and archegonium ontogeny and development, and embryogenesis are investigated. Exosporic gametophytes of A. capillus-veneris came from spores, and ended with the cordate prothallia. Antheridia and archegonia were generally situated toward the posterior end and the notch of the prothallia, respectively. Sporophyte was also studied with emphasis on leaf morphology and the vascular system. There were vascular bundles of dictyostele without secondary vascular tissues. Sporogenesis was scrutinized from sporangial initial of a single surface cell to the annulus shedding spores explosively. Our findings provide insight into the life cycle of the leptosporangiate ferns under experimental conditions, and make it possible for A. capillus-veneris to be an underlying model plant for the study of evolutionary and developmental biology.

Key words: Adiantum capillus-veneris, anatomy, ferns, life cycle, morphology