I've done some reading, but I wanted to get a few more opinions before I come to any definite conclusion on this.

I have a couple plants that have begun doing this:

{{gwi:1292253}}

From what I've seen in my online research, this is the result of either a) too much water or b) an imbalance of root/leaf mass.

This plant in the pic is in a pot, and I didn't think there was too much water in the soil, but I could be wrong.

Other than the rolling, the plants both look very healthy. There is no unusual discoloration in either stem or leaf.

What do you all think?