Linked from
The 22 pages that link to Seed coat, each with the reason it gives.
SeedBroader topic: It shields the embryo and stored resources from damage and drying.
GranivoryBroader topic: A seed coat can resist digestion or mechanical damage from granivores.
Seed developmentBroader topic: It forms from maternal ovule tissue as the seed matures.
Sunflower seedBroader topic: The striped shell is the seed coat of the sunflower achene.