Spread of Green Star Polyps?

[Bob I]

I have a rock that is overgrown with Green Star Polyps (hereafter known as GSP), it looks like a Chia Pet. Today I noticed some patches of a whitish material with what looks like some GSP's growing out of them. Can anyone tell me if that is the method GSP's use to reproduce? If that is so I would calculate I will have a lot of Chia Pets in less than a year from now. :eek: :rolleyes: