Picture?

Sorry about that. I could not upload the photo using my mobile. Also now that I am here on a PC to upload the photo I do not see the EDIT button for my post. This is the seed;

Is it a seed or a seed pod?

It has to be a seed since you can see the cut/dent running along on one side starting from the bottom center and ending on the top. It's hard too like a date seed.

And what country is this in?

The poster is in Pakistan.

Yes. Sorry. I remember replying but don't see my response. Yes I am from Karachi, Pakistan.

I must say that by the look of it, it looks like a pod but I don't know from what. If a seed, I would guess it would be from a tree or other large woody plant. Other than papaya, what are some other trees that grow around you?

Most posters here are in the USA so some other details about your location and its vegetation may help ID it.

FataMorgana

I'll post a photo tomorrow of the whole lawn cause there's a flowering tree with tiny red flowers and the plant needs trimming. Then there are some cacti. And farther away is a tree whose leaves when cut ooz milk. I've seen that kind of tree since childhood and I don't remember ever finding such seeds near it. Other then that there a badly insect eaten Jasmine plant.

Here are the photos of the plants in the lawn.

As I mentioned above, there's the tall papaya plant in the middle two feet away from which I found the seed on the grass.

It might also be a gall of some sort. Certain insects,fungi, and bacteria can cause a reaction in the leaves, stems or bole. Think warts

Looks like a seed from a Jatropha species to me.jatropha seeds

I think I just discovered the tree. I was at my university the other day and spotted the same seeds on the ground below a tree;

These seeds look just the same as the seed I found.

Here's a closeup.

And here's the tree below which I found these seeds;

Now could anybody tell me what this tree is?

I came home that day and saw the seed I picked up was cracking up on the top. So I took a switch blade and peeled off the skin and cut the seed in the middle for a cross section. I regret not having picked up a seed from under the tree at my university, the ones in the photos in the above post.

The seed cut open with the hull in the front and the darker colored core behind it.

How about Polyalthia longifolia (False Ashoka)?

Thanks Dave for your input but I wouldn't say it's a false ashoka. I checked some photos on Google and the false ashoka seems to be longer and narrower like say a closed umbrella Christmas tree as compared to the tree I took a photo of, if you look at my previous posts.

You ought to post a closeup of a leaf.

Here's a link to an image detailing the seed of Polyalthia longifolia suggested above. If it's not P. longifolia it may be a close relative.

http://tropical.theferns.info/plantimages/44e94b75356af766236d4e92386975d1739dda29.jpg

Apparently there is a var. pendula that is commonly planted. Perhaps this one is not 'pendula'.