who coined the phrase phytoremediation? and where did the idea stem from?What plants are used for what toxins?

Answer 1

First methods for field testing phytoremediation were developed by Kathy Banks and her husband.
There are many categories of plants used in phytoremediation. Many brown algae, for example, can be used to absorb heavy metals found in seawater because alginate molecules on their cell walls have a natural affinity for such heavy metal molecules. The nuisance species, water hyacinth Eichornia crassipes, has also been used to absorb pollutant molecules through their roots. There are a lot more examples which can't be fully enumerated here.

Answer 2

Not certain who coined the term, but there are books a-plenty on the subject. Go check out the lockal unicersity library if you can.

Something like:
Plants that hyperaccumulate heavy metals : their role in phytoremediation, microbiology, archaeology, mineral exploration and phytomining / edited by Robert R. Brooks.
Wallingford, Oxon, UK ; New York : CAB International, c1998.
Or
Books on plants and heavy metals.

Dandelions have been recommended for lead cleanup in Russia. Nothing else comes to mind at the moment.

You might tr the Google Scholarly article search.