Xanthosoma sagittifolium ?

Xanthosoma sagittifolium ?;

Attached images may be Colocasia esculenta  (L.) Schott (??). The plant has been growing in my residence for many years. But flowering not seen. Please validate.  
Date :11.08.2014
Location: At my residence (Guwahati)
Family : Araceae
Genus& species : Colocasia esculenta  (L.) Schott (??).
Habitat: Grows on damp places of hilly area
Habit : Herb, Leaf margin purple, petiole bluish in colour   
Flower :Flowering not seen 
efi page on Colocasia esculenta    
Looks like Colocasia esculenta 'Fontanesii' to me.
Since leaves are not peltate, I think this should be Alocasia. Please see the entry in Haines.
To me, the presence of intramarginal vein indicates Xanthosoma. I am happy if the name is Xanthosoma violaceum (the violet one).  But this is regarded as the synonym of Xanthosoma sagittifiolium (the green one). Correct me if I am wrong. 
efi page on Xanthosoma sagittifolium  
I couldn't understand "intramarginal vein". Would you please tell me if the attached picture qualifies for Xanthosoma? Attachments (1).
attached herewith closer view. Attachments (1).
An intramarginal veins is a vein parallel to the leaf margin. So, I think your leaf is not included in Colocasia. Another reason is that your leaf surface is shiny
Attachments (1)

Differences between Xanthosoma & Colocasia:
1. Xanthosoma leaves sagittate, Colocasia leaves ovate, cordate
2. X leaf surface not waxy.  C. waxy
3. X intramarginal vein clear. C. not clear
4. X. rhizome many. C. rhizome only one
Attachments (2)

I thank you very much. The difference between Xanthosoma and Colocasia would help a lot, indeed. Though, in comparison to your point no.1, FoC, FoP, FoNA inform Leaves of Colocasia is ovate to ovate-cordate to sagittate-cordate!
But, that's not a big deal! Last month I have written a number of times, in various thread, that leaves of Colocasia are peltate! I think this should be the first point to remove Colocasia in this scenario and I have already written that in this very thread!
So, my query was difference between Xanthosoma and Alocasia.
As I wrote in my earlier mail, sent you minutes ago, the question is not if it can be Colocasia. The question is - why it can't be Alocasia?
The leaves of both Xanthosoma & Colocasia are also peltate if they are looked based on the the position of the petiole.  But from above it can be sagittate, ovate etc.
It is not Alocasia because the later has stem which can be so long.  Not only inside the ground. The leaves contain a lot of oxallate crystal.  It is only used for feeding gouramy fish (Osphronemus gouramy).
Correct me if I am wrong.
Alocasia is edible, though not all the species or all var., and not throughout anytime of the year. Usually the stocks and/or leaves with petioles are collected after the monsoon and are sold in the market. Some people do not eat it while it is favourite to other people. Since leaves are collected from time to time the wild Alocasia plant do not get much time to grow uninterrupted. My colleagues who eat Alocasia inform me that the stocks do grow 5-6 ft above the ground when they are cultivated in certain region and left in the field for more than a year. In all cases leaves of these plant are shiny/polished. Non-peltate leaves with polished/shiny upper-surface tell me that those are Alocasia, neither Colocasia nor Xanthosoma.
... plant may be Xanthosoma as you have suggested, but I do not know, for I do not have any literature and Xanthosoma is new to me as I have written that in another thread - https://groups.google.com/forum/#!topic/indiantreepix/sHHRMo8ZpaM.
Let's move to the other thread to avoid any confusion.