What does a pinna do on fern?

In ferns, a pinna refers to a leaflet or a division of the frond (the leaf of the fern). Each pinna bears structures called sporangia, which produce spores for reproduction. The arrangement and shape of pinnae contribute to the overall morphology of the fern and play a role in maximizing light capture for photosynthesis. Additionally, pinnae help in water retention and gas exchange, supporting the plant's growth and survival.