Flashkelp

The flashkelp split from its ancestor when some flashstring's found their way up to Chum Temperate Lake. They have grown much larger than their ancestor and have become macroscopic. The also have regained their photosynthesis and that powers the whole organism. It has evolved a primitive root system to bring nutrients up from the soil although at this point their roots are just groups of specialized cells. Flashkelp constantly shed bits of their "skin", with each flake having the potential to grow into a new organism. With little competition they have made a dense covering on the lake bottom, which looks slightly like dark green moss to the naked eye.