Is this fruit edible, please?

What an intriguing thread!

I love your wooden ruler, too, Oldgoat. ❤️ It reminded me of a dream I had recently, in which I had an elasticated measuring tape. It was marvellous for measuring my vital statistics.

It's definitely an alien egg.
I can see a little embryo in there.
Beware, * oldgoat* ?‍♀️

It's a conker, I think. Unripe.
They are horse chestnut leaves

Agree with Calistemon - unripe horse chestnut. I thought walnut previously but I have walnut tree (not old enough for nuts) and leaves are arranged differently.

Whatever it is it's not ripe but I wouldn't be sampling it.

My on line ‘Guru’ suggests walnut

It's NOT a walnut.

I grew up with a walnut tree. Leaves are nothing like that! Nor is the fruit.

So far, having seen the new photos, horse chestnut seems nearest, but I'm still suspicious...

The leaves look like Beech leaves, is the fruit hard like a shell or soft?

My Walnuts are green, I’ll grab one tomorrow and cut it in half and see what it looks like inside. They are almost ripe and I don’t think they will look like the one in the picture.( they don’t normally)

I used an app on my phone to take a screenshot and it came up with Davidia involucrata.

Does it look anything like this?

I think it does

The leaves are different.

It's a conker!

No spikes on it though, is it a Health and Safety Aware smooth Conker?

Oh well we ve got as many answers as people nearly all you can really do is wait for it to ripen and then have another cut through

Old Goat, you could install a free app on your phone, which identifies plants.
That would put us all out of our misery.?

100% sure it is a horse chestnut. Great conkers inside.

Also agree it’s horse chestnut.

Is it a Buckeye tree?
Similar to a horse chestnut but the casings of the nuts are ore yellow brown. The leaves are like a horse chestnut, palmate with a spread of five leaves.

They are poisonous.

More yellow-brown, not green like a horse chestnut.

Callistemon

Is it a Buckeye tree?
Similar to a horse chestnut but the casings of the nuts are ore yellow brown. The leaves are like a horse chestnut, palmate with a spread of five leaves.

They are poisonous.

Oh gosh, Callistomen! For some weird reason that has made me laugh.

I do hope we get a firm identification soon...

Not a walnut - I have a tree here and now!

I'm laughing too but don't know why!

It's poisonous oldgoat!
If it is thst.

It's not beech, they are smaller. We had a beech tree in the grounds of our school and we used to eat the beech nuts. They're mildly toxic, but I remember we thought we could get out of lessons if we were sick .
No H&S in those days.

Why don't you take a piece to a garden centre and see if they can identify it for you.

I may have found it...do you recall if it had pink flowers in spring?

Red Horse-chestnut or eisculus carnea

No need to SHOUT MaizieD

It is a variety of horse chestnut.