An excellent issue of Yard and Garden Newsletter is available at this link.
Have you ever cut open a grapefruit and found a germinating seed inside? I have and mused that it was odd and wondered how it happened.
In the October University of Minnesota Extension newsletter, David Zlesak explains that process.
"The phenomena of seeds germinating while still in the fruit on the parent plant is called vivipary. Some specific varieties of plants are more prone to it than others and atypical environmental conditions can also trigger it. It is common to find germinating seeds within grapefruits or oranges because of storage temperatures atypical from what would be found in nature. Generally, viviparous germination is negative because seedlings soon find themselves with limited resources and die."