May be moving as amino acids. Raises questions about degree of connection below ground. Orchid mycorrhizal fungi are unusual in that they do make cellulases. Furthermore, orchids are unusual in being able to utilize trehalose, a 5C sugar generally used by fungi but not plants. Orchid seeds are extremely tiny and must inititate a mr relationship to germinate and establish.
Some orchids parasitize first fungus, and have to establish new association to live longer.