Musings on Mycoheterotrophs

The recent rediscovery of a plant called Thismia neptunis (Fairy Lanterns) in western Sarawak, 151 years after its only previous record ( leads me to blog about “mycoheterotrophs”.

Thismia neptunis

Thismia neptunis            Image from M Sochor et al.

These are plants like T. neptunis that parasitise fungi and generally have no or very little chlorophyll and therefore cannot make their own food. Until quite recently these plants were commonly called saprophytes – though there was never any experimental evidence to support the myth that these plants derive their carbon directly from decaying plant material. Even the New Atlas of the British Flora (Preston et al., 2002) describes the four higher-plant species of mycoheterotroph in the UK (Neottia nidus-avis (Bird’s-nest Orchid), Corallorhiza trifida (Coralroot Orchid), Epipogium aphyllum (Ghost Orchid) and Hypopitys monotropa (Yellow Bird’s-nest)) as ‘saprophytic perennial herbs of leaf litter’.

Neottia nidus-avis (Bird’s-nest Orchid) is recorded from Skye and Raasay in a few locations – seen here near Fiskavaig in 2009:

Neot nid Skye 2009 2

The mycoheterotrophs comprise over 400 plant species in 87 genera that are parasitic upon fungi, and exploit them as their principle source of carbon. In addition, there are estimated to be over 30,000 species, comprising approximately 10% of the plant kingdom, that depend upon mycoheterotrophy for establishment from dust seeds or spores. (Jonathan R. Leake, Mycologist, Volume 19, Part 3 August 2005 p113-122.)

So ….. never call a vascular plant a saprophyte!

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2 Responses to “Musings on Mycoheterotrophs”

  1. Terry swainbank Says:

    Interesting stuff. I was not aware that Neottia grew on Skye and Raasay. Your picture suggests it is growing in only a lightly shaded area (if at all), quite different to beechwoods down south. Is this another example of a ‘woodland’ plant growing in a much more open situation on Skye cf bluebells, wood anemone etc.?

  2. Stephen Says:

    Yes and no. Not associated with beech here but the image is from a hazel wood – and that is typical hereabouts. Only 4 locailsed sites (plus one 10km square record). The single plant on Raasay was the first VC104 record during a BSBI field meeting in 1969. The Swiss botanist who found it picked it to show to my predecessor and it has never been seen again on Raasay. It is apparently not so rare where s/he came from. I have the specmen.

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