The difference between chestnut and marron has been a subject of discussion especially at commercial level. Often marron is used to define very large chestnuts or, as in the case of the French, used to classify chestnuts which do not have signs of episperm intrusion (pellicle which covers the seed) in the kernel or which have a low division percentage (<12 percent).
However these basic assumptions do not have any biological basis and tend to cause confusion amongst chestnut wholesalers, traders and consumers.
In Italy marron means a particular Castanea sativa cultivar of excellent quality. Of oblong shape, with a reddish coloured epicarp (skin) that is shiny with dense, often raised stripes and small semi rectangular shaped hilar scar. Large sized marrons are not divided, have a sweet flavour, with the kernel itself free of hollows and easily separable from the episperm (pellicle); it protects the seed and is only superficially attached to the nut which makes it easily removable, by mechanical means, also thereby easing the industrial processing. Marron trees are more demanding as compared to other Castanea sativa varieties, in terms of climatic and soil requirements, giving a smaller yield as their husks contain only one to two nuts and have sterile male flowers (andro-sterility).