Daniela: I have not heard anything about it. I looked on dictionary.com and the root is the same as corn, but that doesn’t mean anything. Corn was popular enough (in both usage of the word and eating) that there was a possible confusion. Not so much by acorns.
Interestingly, according to Wikipedia it was a staple food in ancient Spain (unclear how ancient is “ancient). But no one in Spain ever kept Kitniyos anyway so there’s no reason that should affect things. It definitely meets certain criteria for Kitniyos, but we don’t really understand what all the criteria are so we can’t really make our own judgments. Based on this, I would be hesitant to eat them until I learned more, but it definitely seems like an issue worth looking into.