Plants use their leaves to make food from the sun’s energy and carbon dioxide. With very few exceptions of parasitic plants, no tree is known to grow without green foliage — or to be more precise, no tree can start life without leaves or some sort of green tissue containing chlorophyll.
But some may end up as “zombie trees” long after they lose all leaves and large parts of their trunk, either to disease or the chainsaw.
Such undead tree stumps have been observed for almost 200 years, but the evolutionary and physiological processes leading to their existence remain a mystery. One reason is because they are rare. Another is because whatever happens on their journey from feeding themselves to being fed happens out of sight — likely below ground.


The mysterious existence of a leafless kauri stump, kept alive by its forest neighbours (theconversation.com)