Gardeners know it as paparegna as well. Across the whole Neapolitan provincial territory this escarole is grown as a distinct type, and the extra names on the plant are really a map of the leaf: riccia because the blade is so deeply jagged, schiana because those margins stay wide yet lie flat.
What arrives at the table is a large, full head, rustic in look, with foliage that snaps only a little and a flavour that leans pleasantly bitter. That bite is why the green is treated as the essential filling when pizza di scarole is made: the dough wants something sturdy, slightly sharp, and unmistakably leafy rather than a meek salad green.