hanson wrote:

element or compound in tree bark that it burns with too much ash

"Bob" wrote in message
...

"Farooq W"
| More surprising the uptake of heavy metals especially
| Th and U by the plants...Barium is abnormally high or the
| soil on which that tree grew was rich in barium ores!


On Sat, 11 Mar 2006 02:27:31 GMT, "donald haarmann"
wrote:

The up take of uranium by plants is well know. See for example :-
Botanical Prospecting for Uranium on La Ventana Mesa, Sandoval
County New Mexico. US Geological Survey Bulletin 1009-M. 1956.
Some plants uptake serious amounts of selenium.

[Bob]

A Berkeley group is developing the use of a plant for Se
decontamination of soil. It is in field testing. (I could probably
find a ref if someone wants it.)
Then there are the Ni accumulators, which have several percent Ni in
their sap, nicely chelated (citrate, I think).
bob


[hanson]
=1= I posted this into sci.geo.geology in hope to get some views
from the geos' camp about the popularity & effectiveness of BP.
=2= As what/which compound does Si get into solution from the
calcogen silicates, considering that SiO4-- is stable only at
pH 11 in aq?
=3= in what soluble or sol-gel form is Silicon taken up
and transported in/to the plant (at a pH range ~ 7)
=4= As what/which compound is Si stored in the plant?
=5= and what function does the Si have in the plants?


I don't know the answer to your question, but I would look at
Equisetum-- aka scouring rushes. They have extremely high Si uptake. As
a primitive plant whose chlorosphyll is incorporated in the stems, the
Si, is used as a supporting structure.

Also, the Na, K, Ca group are also metals utilized by plants.