Unknown Jelly plant?

This is a Jelly dark green plant (mushroom?) which sometimes I can find along the wall on my garden. THis is a big exemplar and others are like the small egg fish. I usally find them after the rain weather on the ground, along the wall. What is the name of it please? I am very interested. After sometimes, they get dry and very dark.

 

It can be the bacteria Collema

 

is it dangerous or is just the normal bakteria colony.

 

Is there a cherry tree by the wall?

frog

 

no there is no any tree around or near by.

 

I've never seen Collema, so I don't really have an opinion on that. But lichens are harmless (unless you eat them as some are poisonous) and slow growing so if it is there is no worry.

I'm thinking though it might be a species of Exidia or similar jelly fungi. A species associated with soil or buried wood rather than trees/branches. Also not a species to be concerned about. Here's a link to photos posted of Exidia on wikipedia commons -http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=Exidia&go=Go

cheers,
frog