Editing Mycorrhiza (section)

===Orchid mycorrhiza===

{{Main |Orchid mycorrhiza}}

All [[Orchidaceae|orchids]] are [[myco-heterotrophy|myco-heterotrophic]] at some stage during their lifecycle, meaning that they can survive only if they form [[orchid mycorrhiza]]e. Orchid seeds are so small that they contain no nutrition to sustain the germinating seedling, and instead must gain the energy to grow from their fungal symbiont.<ref name="The potential role of Mucoromycotin"/> The OM relationship is asymmetric; the plant seems to benefit more than the fungus, and some orchids are entirely mycoheterotrophic, lacking chlorophyll for photosynthesis. It is actually unknown whether fully autotrophic orchids that do not receive some of their carbon from fungi exist or not.<ref>{{cite journal |last1=Li |first1=Taiqiang |last2=Yang |first2=Wenke |last3=Wu |first3=Shimao |last4=Selosse |first4=Marc-Andre |last5=Gao |first5=Jiangyun |title=Progress and Prospects of Mycorrhizal Fungal Diversity in Orchids |journal=Frontiers in Plant Science |date=2021 |volume=12}}</ref> Like fungi that form ErMs, OM fungi can sometimes live as endophytes or as independent saprotrophs. In the OM symbiosis, hyphae penetrate into the root cells and form pelotons (coils) for nutrient exchange.