The only 2 that I have that are "evergreen" are:

A. Titanum and
A. Verticillatus

Any others that are "evergreen" I am not aware of, you would think there are many.

I am fairly new to this genera and my rule of thumb here in zone 6b is to bring them inside when the nighttime temps reach around 45 F.

I have noticed that some go dormant inside right away and others take a few months to do so, in other words I really only have 2 Species that are in fact "evergreen".

If you do find such a list please post it.

Sorry I couldn't help much.

Have you tried joining the aroid-l mailing list and posing the question there?

you can find the link for the mailing list at the ariod.org site.

I have been folowing all the threads and posing some questions there for about a year now. These are some of the brightest and most highly knowledgeable people you will ever meet when it comes to members of the Araceae family of plants.

Literally the best knowledge about Aroids in the world is shared on this list.

Amorphophallus coaetaneus, one of the most primitive species of Amorphophallus, is evergreen. I grow it outdoors all year in the shade, under an eve. A great species.