Abstract

The reproductive phenology of Hypnea musciformis (Wulfen) Lamouroux was analyzed, over a period of two years, in two subtidal epiphytic populations located in Sepetiba Bay and another intertidal epilithic population on a shore exposed to the open sea. All sites are located in Rio de Janeiro State. These investigations suggest that in this species asexual reproduction predominates over sexual reproduction. There are more vegetative than reproductive thalli under environmentally stressful conditions for growth. Cystocarpic plants were only collected from the intertidal epilithic population and always only represented by a low proportion of biomass whereas male plants were not found. The rarity of gametophytes can probably be explained by the replacement of sexual reproduction by asexual reproduction via apomixis or vegetative reproduction.