This is a probable mutation originating in the Calabrian town of Diamante (CS), hence its name. It is the most commonly found citron cultivar in southern Italy.
It is a small, open, spreading plant, with fairly assurgent growth and very thorny, thick branches.
The leaves are large and oblong, while the shoots and flowers are purplish red and grow mainly in clusters. The large, elongated, ovate-ellipsoid fruit has a broad nipple at the apex. The thick rind is smooth and ribbed, turning lemon yellow when ripe, and is used in the production of candied peel.
The flesh is sparse and dryish, with an acidic taste like a lemon.