Recalcitrant Seed
A recalcitrant seed is sensitive to substantial drying and does not tolerate ordinary dry, frozen seed-bank storage. Mango seed belongs to this general category, which helps explain why freshly handled seed is normally preferable to old, dried seed for propagation. This is different from a hard seed coat that merely delays germination. Protect the living embryo from drying and damage, but do not confuse moisture protection with keeping it in stagnant conditions that encourage decay.