Orange fruit and cross section

Allcitrus treesbelong to the singlegenusCitrusand remain almost entirelyinterfertile. This means that there is only onesuperspeciesthat includesgrapefruits,lemons,limes, oranges, and various other types and hybrids. As the interfertility of oranges and other citrus has produced numerous hybrids, bud unions, andcultivars, theirtaxonomyis fairly controversial, confusing or inconsistent. The fruit of any citrus tree is considered ahesperidium(a kind of modifiedberry) because it has numerousseeds, is fleshy and soft, derives from a singleovaryand is covered by arindoriginated by a rugged thickening of theovary wall.