Scallop (Pattypan) on the market all year.  The squash has a characteristic flared bowl shape with prominent ribbing on the edge giving an escalloped appearance.  The Pattypan derives from a crimped pan used for baking pies.  The squash is harvested when about half grown that is 3 to 4 inches across.  If allowed to continue to grow a diameter of 9 inches is common.  In the white type the squash is pale green when young and becomes whites it matures with a smooth or slightly warted skin and flesh with a green tinge.