Plants used to be "sour ingredients" to food [edible plants]

Beside lemon or limes, what do you use to add sour taste to your food?

Here in Cambodia, I found numerous types of plants that are used in the kitchen to add sour taste to the food! We use them interchange in the daily food. I think we use those plants based on availability, season, and what suits it best to specific dishes.

We used lemon, green tamarind or scratch green mango to add sour taste to this specific soup

Some are best with specific dishes such as it is best to use lemon/lime in the ញាំ/ភ្លា salad but some leaves from the wild for ម្ជូរគ្រឿង "Creamy Sour Soup" What have you known before and what you don't know about these plants?

1. ក្រូចឆ្មា Lemon/lime, very common - the fresh ones are used to add sour taste to ready food or types of salad. Fermented limes are used in the soup named "Ngam ngov soup"
2. អំពិលទុំ អំពិលខ្ចី ត្រួយអំពិល ក្តឹបអំពិល Tamarinds: green and ripe tamarind, its young leaves.. all used in the soups to add sour taste. Ripe tamarind is used in the dip-sauce a lot. They are not just sour, they have some sweet taste which is very good for dip-sauce.
3. ស្វាយខ្ចី Mango: green mango also used to add sour taste to food, 
4. ក្រសាំង Java Cola: they can be used in the soup or add sour taste to the dip-sauce
5. ស្លឹកថ្នឹង​​ river leaf/ Aganonerion polymorphum: used in the soups. They are from the jungle
6. ស្លឹកទ្រមូង ផ្លែទ្រមូង​ Garcinia oliveri: both leaves and fruits are used in the soup for its sour taste. They are from the jungle.
7. ស្លឹកម្កាក់ Hog plum leaves: they are used in the soups
8. ថ្ងាន់ spider tree: used in the soup
9. សណ្តាន់ Fresh garcinia madan: fruits/dry fruits are used in the soup
10. ផ្លែម្ជូរព្រឹក្ស​ ឬ ម្ជូរល្មម Roselle: used in the soup
11. ស្លឹកក្រឡាញ់​​ Velvet Tamarind /[Dialium cochinchinense]: used in the soup
12. ក្រូចសើច Kaffir lime: pickle and used as dip-sauce
13. សត្វអង្ក្រង Red ant: used in the salad ..

Green tamarind being used to scratch and used as sauce in the food

Green tamarind, lemon, and river leaf used in Creamy Sour Soup