Editing Orchid (section)

== Ecology ==

A majority of orchids are [[perennial plant|perennial]] [[epiphyte]]s, which grow anchored to [[tree]]s or [[shrub]]s in the [[tropics]] and subtropics. Species such as ''[[Angraecum]] sororium'' are [[lithophyte]]s,<ref>{{cite journal |author1=Melissa Whitman |author2=Michael Medler |author3=Jean Jacques Randriamanindry |author4=Elisabeth Rabakonandrianina |year=2011 |title=Conservation of Madagascar's granite outcrop orchids: influence of fire and moisture |journal=[[Lankesteriana]] |volume=11 |issue=1 |pages=55–67 |url=http://lankesteriana.org/lankesteriana/LANKESTERIANA%2011%281%29/9_Whitman%20et%20al.%202011.pdf |doi=10.15517/lank.v11i1.18315|doi-access=free }}</ref> growing on rocks or very rocky soil. Other orchids (including the majority of [[temperate]] Orchidaceae) are terrestrial and can be found in habitat areas such as grasslands or forest.

Some orchids, such as ''[[Neottia]]'' and ''[[Corallorhiza]]'', lack [[chlorophyll]], so are unable to photosynthesise. Instead, these species obtain energy and nutrients by [[parasitism|parasitising]] soil fungi through the formation of [[orchid mycorrhiza]]e. The fungi involved include those that form [[Ectomycorrhizal|ectomycorrhizas]] with trees and other woody plants, parasites such as ''[[Armillaria]]'', and [[saprotroph]]s.<ref>{{cite journal |last1=Leake |first1=Jonathan R. |title=Plants parasitic on fungi: unearthing the fungi in myco-heterotrophs and debunking the 'saprophytic' plant myth |journal=Mycologist |date=August 2005 |volume=19 |issue=3 |pages=113–122 |doi=10.1017/S0269-915X(05)00304-6 }}</ref> These orchids are known as [[myco-heterotroph]]s, but were formerly (incorrectly) described as saprophytes as it was believed they gained their nutrition by breaking down organic matter. While only a few species are achlorophyllous [[Parasitic plant|holoparasites]], all orchids are myco-heterotrophic during germination and seedling growth, and even photosynthetic adult plants may continue to obtain carbon from their [[mycorrhiza]]l fungi.<ref>{{cite journal |last1=Sathiyadash |first1=Kullaiyan |last2=Muthukumar |first2=Thangavelu |last3=Uma |first3=Eswaranpillai |last4=Pandey |first4=Radha Raman |title=Mycorrhizal association and morphology in orchids |journal=Journal of Plant Interactions |date=September 2012 |volume=7 |issue=3 |pages=238–247 |doi=10.1080/17429145.2012.699105 |doi-access=free |bibcode=2012JPlaI...7..238S }}</ref><ref>{{cite journal |last1=Gebauer |first1=Gerhard |last2=Meyer |first2=M. |title=15 N and 13 C natural abundance of autotrophic and myco-heterotrophic orchids provides insight into nitrogen and carbon gain from fungal association |journal=New Phytologist |date=October 2003 |volume=160 |issue=1 |pages=209–223 |doi=10.1046/j.1469-8137.2003.00872.x|pmid=33873535 |bibcode=2003NewPh.160..209G }}</ref> The symbiosis is typically maintained throughout the lifetime of the orchid because they depend on the fungus for nutrients, sugars and minerals.<ref>{{Cite journal |last1=Pecoraro|first1=L.|last2=Girlanda|first2=M.|last3=Kull|first3=T.|last4=Perini|first4=C.|last5=Perotto|first5=S.|date=2012-12-01|title=Molecular identification of root fungal associates in Orchis pauciflora Tenore |journal=Plant Biosystems|volume=146|issue=4|pages=985–991|doi=10.1080/11263504.2011.634447|bibcode=2012PBios.146..985P |hdl=2318/93116|hdl-access=free}}</ref>