black spots on Java Fern?

thekoimaiden

Great! I could use some more Java Fern!

Byron

This will add my concurrence with what's been said. The blackish "spots" on the underside of leaves of Microsorum pteropus are sori (the plural of the singular sorus), and a sorus is a cluster of sporangia which are the structures containing spores. They are irregular though mostly round, rarely oblong, and about 2mm in size. They lack indusia in this species; indusia is the plural of indusium, and this is the tissue that covers the sorus in some species.

And this is a true fern, as detailed in the profile.

Chesherca

So now I know. . . and thank you! NOW I WANT to know this:

Why don't BOTH of my plants, or ALL of the leaves on this one plant have these??!

Byron

I mentioned they are irregular, though in the context of my last post that could easily be taken as referring to their shape; should have been clearer.

They are irregular on the leaf undersides, meaning they will be present in varying numbers depending upon the plant. If you look at the photos included in our profile, you will see a few on some of the leaves.