This is what makes the difference in Italian pasta. Italians wouldn't use anything that isn't made from this 'hard' variety of wheat. Most of it comes from the nation's great granaries, Puglia and Sicily. Durum is also widely used in baking, including some traditional southern breads that have been given DOP status, such as Pane di Altamura.
Tumminia (or grano marzuolo) the dark, low gluten, drought resistant grano duro grown in southern Sicily since ancient Greek times and nearly abandoned after the 1950s when more productive varieties were introduced, is the main ingredient of Pane Nero di Castelvetrano and is now being made into a trendy pasta busiate, which taste good with just a dollop of olive oil.
Images by: MarkusHagenlocher, Creative Commons License