As we turn our attention from the sources of umami that are found in the oceans to those that grow on land, we are struck by some important differences. While a great many marine organisms are excellent sources, the number of fungi and plants that would be described as having significant potential to contribute umami is more limited. On the other hand, some are able to supply both basal umami by way of free glutamate and synergistic umami from nucleotides, especially guanylate. And it is among the fungi and plants that we also find a few of the true umami superstars: shiitake mushrooms, fermented soybeans, tomatoes, and green tea.