Strange that the underwater growth isn’t mentioned at any of the other obses here at MO. That is where they develop and where they are able to spread their spores, but they can also be found later on sticks, cones, mosses, etc when the water has disappeared..
If the water stays deep, the stems can be very tall. I have seen them 30 cm, but unfortunately never been able to take a decent picture..

looks like a fit, but does that make sense considering the underwater habitat?

these mushrooms were entirely submerged in running water. I discovered a number of host ‘logs’ which were completely waterlogged and at the bottom of a creek.

My mistake, I meant Cudoniella clavus (I’m mixing up the names)

I agree, this ID doesn’t seem to fit based on the cap color. The observed species were all uniform in color.

Cheers! Jherek

because I know V. truncorum with yellow to orange colored heads:
http://www.fotocommunity.de/...
Regards, Andreas