Java Fern From Nowhere

[JustKia]

I've never had a java fern.
All of my plants were moved from my 33Gal and there has been 2 stems of Cabomba in there for several weeks now along with a small handful of Java moss (and nope it wasn't in the moss I swear).
Today I've gone to put my moss wall in the tank (not finished but I ran out of moss - eeks) and saw this small green thing.
Lo and behold I now have a Java Fern
Any ideas how it got there?
Can they grow from "seed" form or are they always as plantlets?
The only thing I can assume is that I've been visited by the Java Fern fairy!

 

[Nick16]

they can grow from plantlets that form on the ends of the leaves on the mother plant, sometimes when you buy plants, you often get little surprises which can tag along and get scooped up with the plant when you buy it. it really should be attached to something though, depending on its size.
with my java ferns, before i broke down my tank they each had about 20 leaves and 3/4 of the leaves were growing plantlets, howveer i just pulled them off as i wanted the mother plant to grow larger and stronger, rather than putting all its energy and resources into reproducing.

 

[JustKia]

Can't think what it could have come in on. All the new plants went in the 72Gal and there was only the Cabomba and moss in the 33Gal. The moss had been there for months.
How odd that it shows up now.
It's got about 3-4 leaves and the tangly bit (rhizome or roots? or both?) at the base is maybe 1/2" across

 

[aly_starh]

yeh, my java fern grow rizomes and it attached onto Elodea and it grw on the elodea till it fell off. lol
Very fast growing, doesn't need much light

 

[Nick16]

i really dont undertsand the above, java fern is a very slow growing plant, so i dont know where you get your information from, it grows much like the speeds of anubias.

anyway, back to the point, the rhizome will feel very thick and it is where the leaves will appear from, the roots them come off the rhizome. 9rhizome is generally green, roots = brown)
on young baby plants, the rhizome is almost non existent as it is very slow growing, it may only be 0.5cm long if that.

the above is an older plant but you can clearly see the base of the leaves coming out of the rhizome and then the roots below.

Any other Q's fire away.

 

[JustKia]

I must have a very young plant as there is very little in the way of rhizome, unlike my anubias which has a very clear rhizome about 5-6cm long.
It'll be OK left sitting on (not buried) the substrate (like the anubias) or do I really need to tie it to the bogwood?