RE: Java Fern

G'day plant people,

Dave Gomberg wrote-

<AFAIK, there are two genetically different types of Java fern.  At
least two.  I have both and so does Neil Frank and I think Erik Olsen
does too.  Neil calls them narrow and broad leaf, I call them big and
little.   Big has 10" fronds typically, they are cross-shaped (two
pinnae on the frond about 2/3 of the way to the tip) and medium
green.  The frond surface is slightly crinkly.  Little has 2-3"
fronds, they are lanceolate and dark green, with a smooth surface. 
Big grows more spread out, little grows in a clump.

My opinion is that the narrow/small form is probably Microsorium brassii, a species found in New Guinea and Manus Island ( and probably other places too) . Ususl habitat is in small streams at low alitudes between high and low water levels. I have seen it completely submerse in nature growing on rocks and submerged stumps in the streams around Kikori.


Leach G.J. &  Osborne  P.L. :  Freshwater Plants of Papua  New  Guinea.
University of PNG Press,  1985. pages 57-59. 

Under cultivation it seems not to be as vigorous as M. pteropus and the submerse form is much more sensitive to dessication. Try attaching it to lava/ barbeque rock as a substrate so no root rot is initiated from bogwood and it can be easily transferred if it is not thriving.

Bruce Hansen.