Khatmi is a very potent herb for cough and cold, fighting it in one of the best way possible. Most of the throat related ailments can be cured easily through this.
 
A simple formula:
 
5gm Tukhm Khatmi + 3gm Barg Gaozaban + 3gm Peeled Mulethi
This formula is enough to suppress a cough. You need to soak the contents and then boil it. Then drink the water after sifting the solids.
 
To make it much more potent, you can add 2 more herbs.
7 Lesue + 5 Unnab
This combination now becomes extremely powerful and effective. It will completely wipe the cough.
 
The reason being cough mostly is caused by irritation in the throat, and these herbs attack that irritation. Thus giving relief from coughs. Sugar can be added to this combination, to taste.
 
Other Names:
Marshmallow Seeds
Althaea Officinalis Seeds
Gulkhairo Seeds 
गुलख़ैरो बीज