I've been fascinated with Arisaema triphyllum for most of my life, starting when I was 10 years old and my parent's property had wild brush areas full of A. triphyllum, Trillium cernuum, and poison ivy. I would lift each and every hooded spathe to see what color they were, running the gamut from all pale green to near black, various striping, and everything in between. The species is amazingly diverse, and wherever I come across it, the recognition of A. triphyllum is immediate, yet it seems there is always some unique and varying characteristics that set that individual apart. What I like about this one too, is that it flowers late, usually late May or early June.
Just took a quick look through my digital image library, and here's a sampling of varying forms of Arisaema triphyllum. I'm sure you're well familiar with such variation, but those viewers less familiar with this species might enjoy seeing the variation.
1 - veined leaves and light pie-crust-crimped edge, large leaves
2 - dark black-purple spathe and spadix
3 - top half dark spathe, lower portion white, light green spadix
4 - dark spathe, visibly striped on the *outside* of the flower
5 - dark spathe, glaucous purple stems and leaf petioles
6 - attractive form found in nearby woods, low growing, very wide striped flower
7 - another view of the same local form, notice the dark stippling at the base of the flower.
8 - white-veined leaf form, emerging
9 - view from above showing the beautiful leaves
10 - flower is light green and white striped