marimom moss balls, are actually algae. And while that seems like the slime on a rock or aquarium, these balls actually make good houseplants since they do not need much upkeep. take a look now
http://aquariumplantsuk.co.uk/aquarium-plants-category/marimo-moss-ball-x-5-1-free-live-aquarium-plant/
http://www.dailymotion.com/video/x3iseb9