Arum pictum, was Tropaelum azureum etc.
Pacific Rim (Wed, 16 Dec 2009 12:56:29 PST)

Jane wrote:

italicum 'Pictum') turns out to be hardier than
the books say. Some small ones in a well-drained
spot in my garden survived well last winter,
including 17 degrees F and a couple of weeks under heavy snow while in
leaf.>

Here in Zone 6 -- colder, wetter and possibly snowier than where Jane is --
Arum pictum has thrived outdoors for years, with no overhead protection. A
nice colony has formed in our garden; other plants are in pots mulched only
to the rim. Leaf litter descends on both areas haphazardly in autumn; this
is a kind of mulch, of course, but some plants receive no litter and
survive.

I surmise that, as with so many other plants, setting the tubers deeply in a
porous medium makes them more tolerant of wet and cold. I don't know for
sure that they ever freeze, but I suspect that some do, at least
occasionally.

Paige Woodward