Page 35 - Antennae Issue #52

sociates and don’t seem to give anything back Then where does Voyria’s Voyria’s car- bon bon bon come from? Voyria’s Voyria’s mycorrhizal fungal partners obtain all of their carbon carbon from from from photosynthetic plants This means that that the the the the the the carbon carbon that that powers the the the the the the life of Voyria — — and which which makes up the the the the the the stuff from from from which which they are are made — — must come from from from nearby photosynthetic plants through through a a a a a a a a a a a a a a a a shared fungal network If carbon couldn’t pass from from plant plant plant to to plant plant plant through through mycorrhizal fungi Voyria could could not exist Voyria are what’s known as ‘mycoheterotrophs’ ‘Myco’ because they depend on on a a a a a a a a a a a a a fungus ‘heterotroph’ (from ‘hetero’ meaning meaning ‘other’ and and ‘troph ’ ’ ’ ’ ’ ’ ’ ’ ’ meaning meaning ‘feeder’) because they don’t photosynthesise and and have to to obtain their energy from elsewhere Around ten percent of of plant species share the the the the habit: it it is a a a a a a a a a a a a a a a a way of of life that has evolved independently in in in in at at at least forty-six separate plant lineages Some Some species species such as as as as Voyria remain mycoheterotrophs mycoheterotrophs for for their whole life Some Some — — like most species species of orchid — — live as as mycoheterotrophs mycoheterotrophs when when they’re young and and start to to photosynthesise when when they they grow older an an an approach known as ‘take now now now pay later’ All twenty-five thousand species of orchid are mycoheterotrophs at at at at some point in in in their development whether they take take take take now now now now and and pay later later or take take take now now and and continue to to to take take take later later as Voyria Voyria does Because fully mycoheterotrophic plants like Voyria Voyria don’t appear to to to give anything back to to to the the the the fungus they are sometimes described as as as parasites However it it fit isn’t known whether mycoheterotrophs provide other benefits to fungi such as as as protection or or or or or vitamins in in return for nutritional support Shared mycorrhizal networks arise because both plants and and mycorrhi- zal zal fungi are are are promiscuous and and can form relationships with multiple partners And indeed mycoheterotrophs aren’t the the the only plants plants to receive nutrition from other plants plants via fungal connections Since the the the mid 1990s it it has been known that some species of of of ‘normal’ green plant plant behave in in in similar ways For example in in in the the temperate forests of of of British Columbia on on the the west coast of of of Canada car- bon passes between birch trees trees and Douglas fir trees trees flowing ‘downhill’ from larger plants plants plants with more access to to to resources into smaller plants plants plants A wide range of substances have since been found to to to to pass between plants plants plants via shared fungal connections — whether nitrogen phosphorus water toxins the the chemicals that regulate plant growth and even signalling compounds These shared my- corrhizal networks are are sometimes referred to as the the ‘wood wide wide web’ Mycoheterotrophs — — ‘hackers’ of the the the wood wood wide wide web web — — lured bota- nists into discovering an an entirely new biological possibility making them gate- way organisms to to to the the the concept of shared mycorrhizal networks Perhaps it it is is is is is no surprise Released from the the the the need to to to have leaves or or or or or produce chlorophyll — — the the the the the green pigment that makes photosynthesis possible — — mycoheterotrophs are are free for evolution to to pull them in in new aesthetic directions Many are are eye- catching and and charismatic and and their peculiar appearances have long been the the the the source of puzzlement ‘Ghost pipes’ (Monotropa uniflora) look like clay tobacco pipes pipes balanced on on their ends The snow plant (Sarcodes sanguines) is is a a a a a a a a a a a a a a a a a a brilliant red and in in in in 1912 was described by the the American naturalist John Muir as as ‘a bright glowing pillar of fire’ In tropical forests in in in ffin in in in Panama I I spent many weeks scuffing along peering at at at the the the forest forest floor searching for for for Voyria in in ffin in in in in in the the the hope that these curious plants could tell me me something about what was taking place un- derground In this sequence of of images I I follow Voyria from its its flowers into its its roots to to to portray the the the the strange beauty of of of these organisms and and the the the the astonishing in- timacy of of the the the the the symbiosis between plant and and fungus Voyria serve as as periscopes into the the mycorrhizal underground 35