Simplify the following text for a Grade 10 native English-speaking person.
Original: The cultivars of B. oleracea are grouped by developmental form into seven major cultivar groups , of which the Acephala ( `` non-heading '' ) group remains most like the natural Wild Cabbage in appearance :
Simplified: The cultivars of B. oleracea are grouped into seven major cultivar groups , of which the Acephala Group remains most like the natural wild cabbage in appearance :