William,
I get most of my plants on-line as I can never seem to get what I want from the LFSs. Here is the blurb from my main supplier for Java Moss.
''Java Moss'' is the popular name for Vesicularia Dubyana. It is hardy and makes few demands on the water and light. Java moss attaches itself easily to all surfaces, making it suitable for decorating stone and tree roots or hiding aquarium installations. Keep in position with a piece of fishing line until it has attached itself. If growth is too vigorous prune with scissors. Java moss provides a wonderful hiding place for young fish V. Dubyana can also be used in terrariums if the air humidity is high.
Family Hypnaceae
Region South-East Asia
Height 5-+ cm
Width 5-+ cm
Light very low-very high
Temperature 15-28 C
Hardness soft-very hard
pH 5-9 pH
Speed of growth slow
Demands very easy
The only thing I would disagree with is the "speed of growth" - I find that it tends to look like its not doing anything much for a while and then start growing quite well. I have java moss in both of my tanks and until the weekend my older tank had way too much surface cover which was not allowing much light through to the moss, however it seemed to keep on growing fine.
HTH, Eddie