Eskimo words for snow is a famous cliché originating from linguistic academia about the fact that supposedly Inuit have thousands of words to describe different types of snow that other cultures cannot differentiate between. What the equivalent of this phenomenon in your country? What disctintions exists in your language that are not found in other?
In Poland, it definitely has to be mushrooms. It was surprising for me while learning English that Anglo-Saxons don't differentiate between different types of mushrooms on a daily basis. Sure, cooks or hobbists may know the differences between champignon and golden chanterelle, but not the average Joe. Also, most of those names are loanwords, usually from French.
But in Polish, every person since childhood know at least dozen of mushrooms species. Here's the list of all the names of edible mushrooms in Polish.
Also, not as a big of a difference but in Polish, there's a distiction between every other cherry and Prunus avium or wild cherry or sweet cherry. Also in Polish we differentiate between wild strawberry and modern strawberry.
What are those differentiations in your language?