What is the problem with finding a lime in Spanish speaking countries?

http://remezcla.com/culture/lemon-vs-lime-in-spanish/

What happens when you don’t have a separate word for something? You just use a word that is used for something similar. In many Spanish speaking countries, they just refer to limes as lemons. And even if they have a separate word for it, a lot of people don’t even know what a lime is, and they just think that there are two words for lemons.