Little green umbrellas

[newfound77951]

OK, no pic yet but I have what look like tiny green umbrellas on one of my pieces of LR. They are at most 1/8" across and high at the moment, and the umbrella part is flat (OK maybe more like teeny land mushrooms). They are very green, so not a coral, I think. There are also some that are just the stalk with no umbrella but I haven't paid enough attention to see if they eventually grow umbrellas. Any ideas? I'll try to get a pic.

 

[Fluff]

Sounds like a species of caulerpa (Caulerpa Racemosa var. Peltata). I have it going nuts in my tank, it needs pruned often.

 

[Toirtis]

Sound like mushroom polyps reaching for the light a bit.