King's Lomatia (Lomatia tasmanica) is a most unusual plant. In the wild, only a single genetic individual of this shrub is known to be alive, and this colony has existed for at least 40,000 years. When a branch of this shrub falls to the ground, it sometimes establishes roots, and thus can function as a physiologically independent plant that is genetically identical to all other plants in the colony. Which term refers to a clone that is a physiologically independent plant?