Assam lemons are long and thin with a green-ish yellow hue that makes them fascinating to look at. At first glance of an unripe Assam lemon, they look like giant finger/caviar limes. These lemons, also called "Kazi Nemu,” are native to China and Nepal, but you will find them used in a lot of Indian cuisines as well. Assam lemons are also going up in value, (via The Better India).