Recalcitrant seeds are seeds that have to be protected from certain elements, such as drying and freezing, to remain viable.
Seeds must be maintained at temperatures no less than 50 degrees Fahrenheit and does not have long shelf lives. Damage to the seeds results when they are allowed to dry out excessively, damaging the intracellular structures of the seeds, along with the forming of toxic chemicals within the seed.
Recalcitrant seeds can be found in avocado, mango, cocoa and the rubber tree. Acorn, from recalcitrant oaks, is an example of a hardwood seed that will survive excessive drying out.
Image Caption: Cross section of an avocado with a recalcitrant seed. Credit: Thinkstock