Cryptocoryne willisii vs Cryptocoryne lucens

Some say they are different, but according to Kasselmann, C. lucens is a synonym of C. x willisii. According to her, C. x willisii is a hybrid of C. parva and C. walkeri or becketii.

One thing to note with these Crypts is that they vary wildly between tanks, and even within tanks. So some see an apparently different plant and conclude that they must be different.

I have some C. x willisii in a tank, and those growing shaded look completely different from those exposed directly to the lights.

Thanks for the info.

I've read that having lower light conditions forces crypts to grow taller, larger leaves than those grown in high lighting conditions. Is this correct?

Yes, that is correct. In my tanks, the shaded willies grow with upright leaves, reaching a height of ~ 3 inches. Under direct illumination, the hug the ground and reach 1/2 to 1 inch height (not leave length). Actually I should take a picture of that, since I just replanted some from the shade to the front, which makes comparing that really easy.

Thanks for the clarification. If that's the case with C. x willisii, it sounds like it makes a decent foreground plant.