Can these to cross?
Alocasia Colocasia ?
I have tried it 5 times with no luck. Their was a hybrid produced I believe by Joseph Bognor that was very weak and mutated. I am not sure if it survived. Their was a report that odora had crossed with a colocasia from Tony. I think I later read that it was another alocasia form growing among the two other forms. I am not completely sure on this one. It looked like it could have been a hybrid.
I believe some breeding can be made between the two groups the main thing is to have the right species crossing. Some Alocasias look a lot like Colocasias. These would be the ones to breed with. Unfortunatly these species are fairly uncommon and rarely seen. I am growing one species that looks very similar to a Colocasia and I hope to attempt a hybrid if it will ever bloom form me. All my attempts were on Odora which I believe is a little to distant relative to be working with.
That Alocasia in your picture, Brian, is Alocasia hypnosa, which indeed does seem to have a lot of characteristics of Colocasia. In fact, I wrote an article about it; see this link:
http://davesgarden.com/guides/articles/view/1401/
I was going to cross with it this Spring, but I have found the blooms of this plant to be sterile (no pollen), however, which has me thinking that it is already a hybrid, but a mule.
LariAnn
Aroidia Research
If this is true than this is a hybrid already. The flowers are very different and I remember it sends out runners many feet from the base. These are things mainly seen in Colocasias. DNA test would probably have to be done to prove it.