AbstractPhotosynthetic activity of attached sporophytes is very low (a few per cent or less) compared with that of associated gametophyte structures (perianth, bracts and uppermost leaves) inCephalozia bicuspidataandLophocolea heterophylla, or with even small areas of thallus inPellia epiphylla. Photosynthetic uptake of14CO2by developing sporophytes ofP. epiphylla,C. bicuspidataandL. heterophyllais at most a few per cent of the14C translocated subsequently from the gametophyte, and could be negligible. InL. heterophylla, the perianth, bracts and uppermost leaves appear to play only a limited role in nutrition of the sporophyte, the leafy shoots making a major contribution. InC. bicuspidatathe perianth and leaves of the short archegonial shoot may provide a substantial part of the nutrition of the sporophyte. There is some indication in all three species that translocation from the gametophyte is most active when the sporophyte reaches full size but is still green, declining in the final stages of maturation of the capsule.