perisperm

名词 perisperm:

1. the nutritive tissue outside the sac containing the embryo in some seeds

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