Until now none of us did determine the species, neither even Genus.

Have a look on Ziziphus fruit structure, leafs, branches....
It is not Ziziphus sp.

I actually got similar lychees, even a bit bigger with great taste - planted the seeds recently - all grow very well. I must say except its size it was the best tasting lychee i eve ate. Onle negative thing, it was a bit too sweet.

longkong = langsat? I love this fruit! I tried it once !!!!

Fruit looks actually more like macrocarpa
Strange because macrocarpa seems to be described from more southern regions according to some papers.
Or lets better say, before all was described as acrocarpa and later the different plants of northern distribution were divided into another specis H.heteroclita.
So actually intresting. do you think both species may be found at same territory?

The last two photos could be of Horsfieldia kingii
The fruits  belonging to  Cucurbitaceae family  are from wild plants.
Once identified,I can get them.
I will have many interesting species in near future

Roy

Thank You dear Digpati - All could be intresting I suppose!
Horsfelida is also very intresting species, but don't know if the orange aril is also edible like in Myristica fragrans?! Seed is most probably not to use for food puroses..but i am not sure

Second picture seems some Cucurbitaceae and third Zingiberaceae. Have too lokk what species they may be. First Picture  seems a Ficus sp. - maybe Ficus palmata:
http://www.flowersofindia.net/catalog/slides/Punjab%20Fig.html
or Ficus fulva:
http://vietnamplants.blogspot.it/2014_05_01_archive.html
or Ficus hirta, that has various varieties in India.

As the picture is not to clear please use this file for help:
http://tai2.ntu.edu.tw/taiwania/pdf/tai.2012.57.2.193.pdf
To me it looks similar to F.fulva on the picture I posted. But on other pictures F.fulva looks different ...

Calligonum junceum:
http://cvh.org.cn/cvh_picture/eco/b/1210845.jpg
Calligonum calliphysa:
http://botany.cz/foto/calligonum1.jpg

Me myself i tried only Calligonum aphyllum:
http://www.plantarium.ru/dat/plants/6/623/623_45136c4a.jpg


Fruits are collected before they dry out. Taste is light sour - apple like.
Don't know, but may assume that excessive consumption of fresh fruits isn't good for Oxalates present in the plant. (Most Polygonaceae, like rhubarb, produce oxalates..).
Calligonum are plants of extreme desert climates. And are both winter and drought hardy

Maybe Phyllanthaceae/Euphorbiaceae??
But still - difficult without flower, seed, leafs....
I don't think its Allophylus at the end - I simply tried to search plants from Kerala that correspond. But without flowers and without knowledge on fruits inside from the Keralite flora - difficult for me

Except its great nutritional value it is also a very beautiful plant! I think it should earn really attention!

May it be some Sapindaceae?

Don't have any experience with Anacardium, but with Mangifera, PIstacia vera and Bouea - all Anacardiaceae...
All, specially Pistacia vera develop long taproots.
Pistacia is extrem in this sense.
You may use the smallest pots, but they should be deep, I think. If you cannot find such pots use a plastic tube cut in pieces.
That may solve initially your place problem.

I am not a Passiflora specialist, but second one looks like P. suberosa. However seems that this species may vary in leaf shape:
https://florafaunaweb.nparks.gov.sg/special-pages/plant-detail.aspx?id=1469#