Enclosure of the nucellus by the integuments is incomplete, the embryo sac or, in gymnosperms, to the archegonium.
Enclosure of the nucellus by the integuments is incomplete, the embryo sac or, in gymnosperms, to the archegonium.
珠被并不是将珠心完全封闭，而是留有珠孔以便受精时花粉管进入胚囊，或裸子植物的藏卵器。