There's no rule saying you can't mix vegetables and ornamentals in the same garden. Furthermore, some gardeners line out ornamentals in the vegetable garden while they bulk up or until space becomes available elsewhere. Providing each has sufficient space and ornamentals do not interfere with cultivation and harvesting there is no problem.

It may be a variegated Plectranthus. Here is a link that might be useful: images of variegated Plectranthus

Thank you, deejaus. Looks like it!

Oh dear! I was hoping that it wasn't the air potato because I've heard how invasive they were. Now the real battle begins...trying to rid my yard of them. Thanks again to u both!