Dollarweed is a broadleaf weed that appears in wet areas in the landscape. You may also have heard it called "pennywort."
It's low to the ground, with one round leaf per stalk. The leaves can grow up to the size of a silver dollar—hence the plant's name. It looks similar to a lily pad.
Dollarweed usually appears in places where a gardener has overwatered or in naturally wet places, so adjust your irrigation or improve drainage in the area.
To get rid of dollarweed, you can hand-pull it, as long as you make sure to get all of the white rhizomes as well as the plant itself.
You can also use either selective or non-selective herbicides to control this pest. Be sure to read the product label and follow all instructions.