Costata Romanesca (ribbed Roman zucchini) is a mottled, slightly belled squash distinguished by pale, raised ribs that run its length. It is one of the striped and ridged types that are still likely to be called cocozelle rather than zucchini. Although more flavorful than the bland commercial zucchini, it is problematic as a market item, for it quickly loses its vigor and savor. When solid and young, it is juicy, refreshing, and summery-sweet, but it quickly turns bland, flabby, and rather bitter. Seek it out at farmers’ markets, where it will be freshest. Cook like classic zucchini.
