Arum ID assistance

[Bwosczyna]

Hello:
Member Susan in southern Ontario, Canada has submitted the attached pics in hope of an ID.  Quite obviously an arum, but I don't feel qualified to nail down species, so I'm posting in her behalf.  I think it may be maculatum.

"It is currently growing among hardy geranium, in a protected area between a walkway and a wall, in dappled sunlight under the canopy of a mature juniper. It receives morning sun and otherwise, reflected light and shade. It has endured temperatures of at least -20C. This area does receive moisture.

The leaves are 5" long and 3" wide. The growing period is Feb-Mar to May; dormant Jun to Sep; restarts Oct thru Dec; dormant Jan. I've been trying to get the plant ID'd for three years without success. I believe the plant has bloomed before, but unfortunately I don't have any photos of it blooming. It would be at least five years old, and could be older."

Bridget

[CG100]

It does look very much like maculatum, but italicum is so variable too.

Although maculatum can cover the ground well enough, it seldom makes significant tight clumps of leaves, whereas italicum normally does.

Probably maculatum.

[Uli]

Doesn't Arum maculatum have black spots and not white ones as seen on the pictures?
I grow quite a few Arums but without flowers most of them are lookalikes.

[Martin Bohnet]

Maculatum actually has no spots at all in vast areas of origin - at least here in southern Germany.

The point of survival of -20°C should likely minimize the possibilities: maculatum and cylindraceum definitely, italicum, besserianum and orientale maybe, judged by distribution data from potWo

[CG100]

Maculatum actually has no spots at all in vast areas of origin

Here in the UK maculatum can be found with all the patterns above. Varying amounts of brown spots (some look black at a distance), usually small, is common, plain leaves are by far the commonest.