Unknown Plants: Part 2

It's been a week or so...my unknown plant is growing nicely. I still don't know what it is, but my original guess looks likely. The edges of the leaves are increasingly serrated or runcinate.

Another plant has entered stage left, a demure white flower, about eight petals, very small.

The plant right now is about four inches high, alternately placed leaves, obovate in shape.

Busy week for me, I'll probably not be able to spend any time keying out the identification of these unknown plants, but the photos should help me later when I do have time.