basal placentation: where one or few ovules develop at the base of a simple or compound ovary
placentation: arrangement of the ovules in the placenta and of the placentas in the ovary
cycadopsida: palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta)