The exocarp is the outermost region of the pericarp. It forms the external covering of the fruit wall, outside the mesocarp and endocarp. The skin of a peach illustrates the term.[ref]
The exocarp belongs to the fruit, whereas the seed coat belongs to the enclosed seed. They may both act as protective coverings, but function alone does not make them the same structure. In a caryopsis their close attachment can conceal the distinction; tracing their origins to ovary and ovule respectively preserves it.
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