Gnocchi is a variety of dumplings generally made of which vegetable?

Gnocchi is a varied family of dumplings in Italian cuisine. They are made of small lumps of dough most traditionally composed of a simple combination of wheat flour, egg, salt, and potato. Variations of the dish exist, where individuals often supplement the simple recipe with flavor additives, such as semolina flour, cheese, breadcrumbs, cornmeal, or similar ingredients, possibly including herbs, vegetables, and others.

Source: Wikipedia