Don't think either fit Peter.

"Mycoheterotrophic plants are nonphotosynthetic parasites using fungal
intermediaries to withdraw nutrients from other plants" From which other
plant is the orchid drawing nutrients?

"holoparasitic plants - no direct contact of the parasite with its host
plant" This implies that the orchid is a parasite but what is the host
plant with which it doesn't have contact?

JV

"P Max" wrote in message
...
How about these, John and Co: 'Myco-heterotrophic plants' and
'holoparasitic plants'
"Mycoheterotrophic plants are nonphotosynthetic parasites using fungal
intermediaries to withdraw nutrients from other plants"
holoparasitic plants - "no direct contact of the parasite with its host
plant"
see:
http://www.biosci.ohio-state.edu/~aw...evolution.html

--
)
"John Varigos" wrote in message
om...
Hi Dave

Found this from a paper by Martin Bidartondo and others in Molecular
Ecology (2001) 10, 2285-2295.

"Epiparasitic plants are nonphotosynthetic and they obtain fixed carbon
from other plants via a shared mycorrhizal fungus. This behaviour makes
them cheaters of one of the most pervasive mutualisms in terrestrial
ecosystems. There are several unique features of epiparasitic cheating
that make it a system likely to yield novel insights into symbiotic
interactions.

First, epiparasitism involves a plant-fungal mutualism, whereas our
understanding of cheating is based on animal (almost exclusively insect)
interactions.

Second, the photosynthetic host does not interact directly with its
epiparasite. Thus, because there is no opportunity for the photosynthetic
host to select against its epiparasite without selecting against its own
mutualist, an 'unholy alliance' is forged between the epiparasitic plant
and the mycorrhizal fungus.
Third, it is a system that combines an intimate interaction (i.e. one
with cell to cell contact) with a diffuse one (single fungi associated
with multiple plants and vice versa)."

Does that make it clearer? ;-)

John


"Dave Gillingham" wrote in message
...
The inflorescence just had that look about it.

I really don't know the difference between saprophytic & epiparasitic.
I have
this feeling I've heard somewhere that a saprophytic relationship is
mutually
beneficial to the orchid & the fungus; whereas epiparasitic involves the
orchid
parasitising the fungus it relies on for nutrition, to the detriment of
the
fungus. Can anyone comment?

On Wed, 5 Dec 2007 20:41:37 +1100, "AusDigi" wrote:

One reference says its saprophytic while another says epiparasitic,
though
it doesn't mention the parasite it might be parasitizing.


"Dave Gillingham" wrote in message
m...
Would that be saprophytic, Reiner?

Dave Gillingham
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