Could it be Alocasia portidora? Seems like the two hybrid odoras could have gotten mixed up. Probably not A.borneo giant, because it looks basically the same as A.macro, just gets huger(if that's a word).

Definately not a Alo. Portidora, I have several of those. I forgot to mention in my original post that the leaves are much rounder than the Calidoras and getting bigger given that the plants are the same height.

Your mystery plant sounds like it could be a type of A. macrorrhizos. The one you have as A. macrorrhizos but that has a closed sinus (what you described as the leaf tissue stopping short of the stem) could actually be a type of A. odora. Quite a bit of variation exists in that group. I take advantage of it in my hybridizing work.

All the true A. macrorrhizos I know of (including Borneo Giant) have an open sinus, or the leaf lobe tissue separated all the way to the petiole, or leaf stem.

LariAnn
Aroidia Research

Here is a link that might be useful: Example of A. macrorrhizos leaf

Thank you LariAnn,

The leaf's open sinus looks exactly the same as the leaf in the picture you attached to your post but the leaf on my plant as a whole is much rounder so as you say, almost certainly a form of Macrorrhizos.

Thankyou for your help, I knew it was'nt a Calidora so that has pleased me. I am hoping it is a 'Borneo Giant' I stumpled upon because they are not available here in the UK or so I thought.

Chris. UK.