Wilbert Hetterscheid refers to them as tubers....as he is the worlds number one expert on the genus having described most of them I will defer to his nomenclature. They certainly seem to be a tuber to me....potato being the classic and these guys looking like small taters. Maybe too much time :o) Dan

Taro (not amorpho) form corms. I really see nothing in the definition of corm and tuber that can be used to distinguish the two. Both are formed from underground (or above ground) stem material. Bulbs come from leaves and tuberous roots come from roots. Potatoes are made from underground rhizomes (which is stem) material.

Corms are made from short vertical stem parts whereas tubers can be made from either horizontal or vertical and can be long or short. So I guess a corm is a kind of tuber.

If you have seen how the A. Konjac spreads it sometimes sends out long horizontal swollen tubers sideways. Since they are both long and horizontal that would seem to violate the rule of the corm being short and vertical. I would say they count as tubers. Doesn't mean other amorphs wouldn't rightly be classified as forming corms if they always produce short and vertical storage stems. I think you might even get away with saying that Konjac forms both tubers and corms.

A corm is a specialised kind of tuber, the live part of (usually) one year's duration. So, all corms are tubers but not all tubers are corms. The distinction between rhizomes and tubers is far from clear also.