<P> Aquatic CAM plants capture carbon at night when it is abundant due to a lack of competition from other photosynthetic organisms . This also results in lowered photorespiration due to less photosynthetically generated oxygen . </P> <P> Aquatic CAM is most marked in the summer months when there is increased competition for CO, compared to the winter months . However, in the winter months CAM still has a significant role . </P> <P> The majority of plants possessing CAM are either epiphytes (e.g., orchids, bromeliads) or succulent xerophytes (e.g., cacti, cactoid Euphorbias), but CAM is also found in hemiepiphytes (e.g., Clusia); lithophytes (e.g., Sedum, Sempervivum); terrestrial bromeliads; wetland plants (e.g., Isoetes, Crassula (Tillaea), Lobelia; and in one halophyte, Mesembryanthemum crystallinum; one non-succulent terrestrial plant, (Dodonaea viscosa) and one mangrove associate (Sesuvium portulacastrum). </P> <P> Plants which are able to switch between different methods of carbon fixation include Portulacaria afra, better known as Dwarf Jade Plant, which normally uses C fixation but can use CAM if it is drought - stressed, and Portulaca oleracea, better known as Purslane, which normally uses C fixation but is also able to switch to CAM when drought - stressed . </P>

Where does the calvin cycle take place in cam plants