Water Gardening: Floating Sensitive Plant, 2 by FountainMan

FountainMan wrote:
The other day I bought a Floating Sensitive Plant. I think these are the coolest things. Anyway, it was growing in a pot when I got it but is commonly grown as a floater. The stems are developing this growth that looks like mold. On another water garden forum I was told this was just the plant adapting to being a floater by developing floating tissue. If anyone else has this plant can you identify this?