what native Texas trees are suitable for the phyto-remediation of lead or chromium.?

Answer 1

I've read in a magazine that common ragweed is suitable for absorbing large amounts of toxic metals through their root systems. (I'm sorry that I can't recall specifically WHICH magazine.) But ragweeds grow very quickly compared to trees, and they can be harvested and burned before they give off their pollen in the fall. Burning drives off the hydrogen, carbon and oxygen, and the ash that is left is an enriched ore for the metals, up to ten percent metal. I believe that they are capable of taking up chromium, which otherwise forms very toxic compounds.

You might possibly be able to find out more about how much of those metals are taken up by different plants by searching on 'metal poisoning of plants', or 'limits of plant growth due to planting in contaminated soils'. Good luck!