详细解释:【医】 外胚乳
英语解释：
名词 perisperm:
the nutritive tissue outside the sac containing the embryo in some seeds详细解释：
per.i.sperm
n.Botany （名词）【植物学】 The nutritive tissue that is derived from the nucleus and surrounds the embryo of the seed.外胚乳：包在种子胚芽外，产生于细胞核的营养性组织