What we call "marmalade" (which, by the way, can be any fruit jam, but we have narrowed it in the US) would be "mermelada de naranja".
I allus thought that marmalade was made from a citrus fruit and there had to be bits of rind in the final product.
Lemme go look it up:
[url]
http://www.bartleby.com/61/68/M0116800.html]AHD[/url] says "especially citrus fruits."
I always thought it had to be orange, but such is not the case. As you wrote, "especially", not "always", which is indicative of usage, not actual meaning.
Try this one:
http://dictionary.reference.com/browse/marmalade This indicates that the origin of the word had to with quinces, not a citrus fruit! The quince connection appears in all the sources I checked, including your Bartleby's. :0)
