[marcosdumay]

What is the difference between a very cooperative colony of independent single cell organisms and a multi-cellular organism?

On practice the only difference is on the level of collaboration. You get a similar phenomenon here, it's different because those plants collaborate less than the leaves of a single plant, so we give them a different name. From that point of view, this finding is quite boring. What makes it interesting is that it's an independent evolution of collaborative behavior.