Donald R Smith wrote:
I have found a brownish fungi on the underside of the leaves of my
Elkhorn. Last year I noted the same fungi when it killed off each
infected leaf commencing at the tips and working back into the plant.
The top of the leaf gets a series of brownish dots which show the
complete coverage of fungi on the underside. The fungi first appears
as a shaded area and develops into a raised growth four to five mms
in height. I have been cutting away the infected areas which seems to pull
it up
short. However, is there a spray I could use and does this fungi have
a name?
thanks,

Don

This sounds to me like this is not a fungal growth but part of the fruiting
body of a fertile frond. See these pics:

http://en.wikipedia.org/wiki/Platycerium

The one on the lower left (Platycerium superbum) shows a fertile frond
hanging down below the others with the thick brown lining.

Is there any chance of a picture of yours?

David