It'll just be the mycelium of a fungus - many develop a symbiotic relationship round the roots of plants, helping their growth. If the soil was dry, you'll have noticed it more. It's unlikely to be anything that might have damaged your plant.

Thanks Bamboo, it's good to know that it's nothing too nasty. have given it a pot all to it's self; The soil was a little dry another plant had started to invade it's space, It has ben sulking though.