Clay has the greatest water retention and what effect will this have on the soil, and on the plants living in the soil?

Explanation: Plants can grow in clay as well, plants can grow in anything as long as it has a place that can supply water to the roots. Clay can be in dirt as well. But it also depend on the kind of clay. Clay can be made by very dry almost powder like dirt and be made into a thick clay, (this how you make bricks) But. Of clay drys its like conctre and that would not work.