A plant — to me, reminds me of all the elements of nature, except for fire, I guess… at least, not in my garden.
A running river — a symbol of water — stands as one of the most powerful elements of nature after fire.
A ball of fire, but kept at a safe distance from us.
Air — wind, they stay invisible and can only be seen when the trees and leaves flutter or clouds drift away. Of course, even this could show us its temper sometimes.