Answer: You probably have what is known as a sour orange tree. They were often planted for ornamental reasons. They look good, but the fruit is highly acidic. It can be used to make marmalade. Another possibility: 'sour orange' rootstock is often used for its dependable growth characteristics, with a sweet orange variety grafted onto it for better fruit qualities. Sometimes the grafted variety will die back and the root stock variety takes over. As for the white spots, without more detail it's difficult to say. Citrus tree trunks are often painted white as protection from sunburn. Could it be leftover white paint that has faded out over the years? If not, please send another email with detail on the spots: how big, all over the tree or localized, sticky, etc.
Q&A Library Searching Tips