柯林斯英汉双解大词典
nucellus /njuːˈsɛləs/
1.N the central part of a plant ovule containing the embryo sac (含胚囊的)珠心[1]
nucellus embryo 珠心胚
degeneration of nucellus 珠心退化
degenerated nucellus which 珠心组织[1]