Is it growing separately from the Java? I had something similar, and it was growing out of the moss, almost like new shoots. Never looked into it any further though.
Yes it's growing almost on top of the java moss. There must have been a small shoot in amongst the java moss when I got it and its just grown from there
its defo riccia, once youv got it in a tank you'll never get rid of it, unless you over dose liquid carbon, it doesn't like that.. but it still outgrows it. it also hops tanks somehow