What is the primary ingredient used to make the most common variety of Italian 'Gnocchi di patate'?

Potato

While gnocchi can be made from semolina or flour, the potato version became a staple in Italy after explorers brought the tuber back from the Americas in the 16th century. To get the perfect texture, chefs recommend using starchy potatoes, which hold less moisture and prevent the dough from becoming gummy.