Hampshire,
United Kingdom 
Does anyone know the name of this?
It is growing on an old buddlia. The buddlia is on it's last legs, due to weedkiller drift a couple of years ago I suspect, not this thing, there are more than just this one on the plant
I think they are just taking advantage of the dying wood, not killing the buddlia
I'm only curious as to name, I don't want to get rid of it, and I'm quite happy to let nature continue
The older ones seem to have deflated so I guess they are full of some type of gas?
22 Feb, 2021
Answers
This is spectacular! I'm quite envious. Have you tried cutting one in half to see what the structure is like? (One that hasn't deflated if there is one) Is it solid, full of pores, jelly like etc. How big is it? Just joining in to see the answer if anybody knows!
23 Feb, 2021
Yorklass, not tried cutting one open but now I will
Watch this space
24 Feb, 2021
Rhodotus palmatus?
See webpage: https://en.wikipedia.org/wiki/Rhodotus
25 Feb, 2021
Longleaf, similar but different IYSWIM.
Colouring is wrong & mine does not have a cap / stalk, but as your link shows even the experts can't agree on it
I di look for one to cut open but once deflated there is just a dark skin / smear on the wood, so nothing to really look into without a microscope
25 Feb, 2021
can I ask what does IYSWIM mean please?
25 Feb, 2021
Sorry SBG, IYSWIM = If You See What I Mean
One of the Internet's many acronym's, hangover from limited letters when texting
26 Feb, 2021
Previous question
well I haven't seen a fungus like this before. If it has deflated then I suspect it has shed its spores. I wonder if it is related to a puff ball.
Some replump when the air is damp, such as the jelly ears.
I will continue to look through the various guides I have.
22 Feb, 2021