"Scott Nichting" wrote in message
.. .
Some of the leaves of my Java fern are getting brown spots on the back of
them. Each spot is about 1/8 inch in diameter, and 1/16 inch high. They
appear in 2 uniform rows down the back of the leaf, one row on each side
of
the main "vein" running the length of the leaf. They are fairly well
attached to the leaf, a rough flow of water or light brushing with the
hand
will not remove them, but they come off without too much trouble with a
fingernail. On an otherwise healthy plant only a few leaves have these
spots,and the ones that do have the full 2 rows the whole length of the
leaf - there is no in-between. Anyone know what this is and/or what
causes
it?

--
Scott Nichting



The spots are called Sporangiia, they are sacks that contain the spores that
ferns use to propagate. The spores themselves are usually microscopic (or
very nearly so). The Sporangiia will open and release spores, when the
spores land on a suitable surface they will begin to grow into a small
(usually heart shaped) plant called a Prothallia, after a bit the prothallia
will develop into an adult fern... Or at least that is how it works with
most ferns, there are exceptions, and I don't know the particulars of
aquatic plants.

These growths are nothing to worry about, most of the spores will not
survive, in fact most of them will go into your filter =p. Of those that do
reach the prothallia stage, only a few will become adults.


Hope this helps

--donovan