Mysterious perennial

Hi,
I have this mysterious plant that grows in a tub in the garden.
It seems to be a perennial as it sends up 2/3 stems each year then dies away in the winter (4 years now).
But i've never seen a flower on it but despite this it seems to be spreading as i'm discovering them in different areas of the garden.
The pic shows it at the end of its life, altho when its a new shoot the leaf comes up as a single & only splits as it grows.
Any information would be apreciated.

 

Its a Voodoo lilly.http://davesgarden.com/guides/pf/showimage/41321/

 

There are a few plants refered to as voodoo lillies but I think your plant is Sauromatum venosum, also it gets called Typhonium venosum.

I believe both are the same plant or at least the differences are very small.

They actually flower, before the leaves form, in May or June.

A corm needs to be a fair size before it flowers.
It fairly hardy but not totally and hard frost can kill the corms.

 

Thanks for that, i've taken a look at the pics & your spot on.
Havent had any flowers yet but some of the leaves get quite big so here's hopeing for next year

 

Should I point out that Sauromatum, like other Aroids, grows from a tuber rather than a corm? :D