Scallopini squash are sometimes called pattypan squash. These summer squashes are usually harvested at a small, immature size, just a couple of days after pollination. This is the stage when they are the tenderest and sweetest. If your goal is to save seeds from mature scallopini squash, just remember that they are in the diverse species Cucurbita pepo, so they need to be isolated from other C. pepo in order to avoid cross-pollination.