I have a question. I have always understood from reading books about
orchids that they are not considered parasitic. However, I came across
a newspaper article from Malaysia that states just the opposite. I
would be interested in comments from those more knowledgeable about
orchids than me (that would be just about everyone). Thanks

http://thestar.com.my/lifestyle/story.asp?file=/2004/9/7/features/petalspur&s
ec=features

Here's an excerpt:

...For all their diversity, orchids share one common trait: they rely
solely on other organisms, particularly fungi, to survive b a
characteristic which Jutta says is quite distinctive and serves as a
source of confusion to scientists.B 

"Fungi play a crucial role in the biology of many plants because they
convert oxygen to compounds that plants can use to grow, but orchids
depend on fungi well into maturity." Beneath their good looks, orchids
are parasites, says Jutta. "This conclusion was established only at
the beginning of the last century, and after much debate, it has
finally been accepted and scientifically proven.B 

"Orchids use fungi as a means of nutrient transport. The plant even
produces sugary matter for the fungi, which feed on carbohydrates, to
attract them."B 

Once the fungus penetrates a certain point within the plant's cells,
says Jutta, the cells will secrete an enzyme that breaks down the
fungal tissues, keeping the fungus in check and preventing it from
invading the plant further.B 

The dissolved fungal tissue is then broken down into vitamins, fatty
acids and carbohydrates which the plant uses for its own growth.B 

"This cycle is repeated over and over, and each cell is re-colonised
several times." This process, she adds, begins as soon as an orchid
seed germinates.B 

"When a seed's outer shell is broken, it is 'invaded' by a fungus, but
the seed contains the enzyme that keeps it in check, not allowing the
fungus to destroy it."B 

Once this happens, the fungus is not killedbut it simply becomes a
vessel through which the orchid derives nutrients for its own
development, says Jutta.B 

--
www.pollenatrix.com
"Botanical discipline, daily."
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