Mystery growth mainly on plants...

I've fot a mystery growth in my 45 gallon.

A little over a mont ago we removed a number of silk plants, and
replaced them with Anacharis and "water sprite". Both are weeds, and
have been growing great. They have really added a lot to the tank.

In the last few weeks I have noticed a growth on the Anacharis. It is
a deep blue-green color, and at first I thought they were roots,
however I quickly noticed that they were growing up, not down or out.

Initially one grouping was covered by a fine covering of light hair
like filaments. In the last week these fine hairs have grown and
thickened. Some of them are two inches long, and quite strong.

Over the weekend I noticed a couple of pieces waving in the outflow
from the filter. Four days later, the longest is almost 5 inches
long.

They are not straight, but rather fork like veins or roots. I tried
to take some pics but they are really rather hard to get.

Any ideas???

TIA!


--Tony