Pl identify this plant

Hi,
I have these plants/weeds growing in my backyard in my private house in Atlanta, GA, USA. I first started noticing them a 45 days back in June. Within a month, they have grown to this size. There is a distinct scorpion shaped spot on each of the leaves.
I don't see these plants anywhere else on my backyard except a 40 sqft area. This particular area belongs to my raised Plant Bed where I was planning to grow some vegetables.

Could you please tell me what kind of plants are these?

Thanks

 

Maybe Ladysthumb (smartweed).

http://extension.umaine.edu./cranberries/files/2010/02/Ladysthumb-Smartweed-070807.jpg

 

Two species (and maybe some others) are very close and both have maculas on the leaves:
Persicaria maculosa (Polygonum persicaria)
Persicaria lapathifolia (Polygonum lapathifolium)

 

Thank You very much.
This is exactly I was looking for.