I agree with your Usha, it can be invasive, heck just rip a piece or two out, plop it in a hole somewhere and away it goes! Those little blue faces are very nice, I just rip it out if it gets into somewhere I don't want it.

Susie

Run for your life! This is the single most invasive plant in my entire yard. It doesn't just spread out; it *jumps* all over, coming up in places far from the original plant. Impossible to get rid of. And, yes, it's so innocently pretty; a cunning ruse if ever there was one...

Does this plant come in a red and purple version? I bought a plant last year that looks a lot like this but with the different coloration. It hasn't been invasive yet, and I'm hoping it's not. I really like the cute little faces on it. :)

I wonder if you're thinking of "Bat-faced" Cuphea? (This link is to a bloom pic pretty magnified).

Here is a link that might be useful:

ddiverblue,
are you thinking of wandering jew? If you do then they are all related in Tradescentia family.

Pagancat nailed it. Talk about being a magnified picture! At least now I know what they really look like.