Its other names include Bog onion, Brown dragon, Indian turnip, Wake robin and Wild turnip
Its mature height is a foot or two(some say 4-feet) and it's gorgeous flowers bloom in late spring, April to May.
Two large green leaves (1-1.5' long), with three leaflets grow upward from a single stalk and provide shade for the flower.
The flowering plants start out life as males and as the clump grows, the plants become hermaphroditic with male flowers on upper part and female on lower part. The colony disappears over the summer, becoming dormant. When mature, plants will produce clusters of red berries in late summer.
Dennis Kalma adds to their mystique -
"Also, the sex change is reversible. A female plant which has had a bad year because it was trampled or eaten by slugs may not have enough energy stored at the end of the growing season to support a female flower next year. It may therefore produce only a male flower or perhaps no flower at all. This process is again reversible, so that after a few good years the plant may again produce female flowers.
This plasticity allows the plants to adapt to changes in their environment. They need not be locked in on a particular response that they may not have the resources to support. Each plant optimizes its chance to contribute to the next generation of jack-in-the-pulpits by making a developmental decision about what kind of flower to produce next year. The actual decision seems to be based on the amount of starch stored by the end of the summer."
They are pollinated by fungus gnats.
Some people are sensitive to the calcium oxalate in the roots (same as in Diffenbachia or dumb cane) so they are considered poisonous.
The Pacific Bulb Society has information on a wide variety of Arisaemas.
"The plants may have different sizes and colors in the leaves and in the spathes. This was well described by Roy Herold, (MA) who wrote: "I posted a description of the A. triphyllum that grow wild in the woods next my house. In an area perhaps 100 feet square, there is almost every variation in coloration you could imagine: spathes go from all green to white striped, to green on the outside and red on the inside, to nearly black all over; the spadix can be light green, green speckled with red or almost black; the stems too from green to dark red and leaves sometimes have red veins. A single plant can have any combination of these characteristics."
Also see their page of Arisaema here.
Native Americans used it as a treatment for sore eyes, rheumatism, bronchitis, and snakebites, as well as to induce sterility.
Meskwaki Indians states chopped the corm and mixed it with meat for their enemies to find. The oxalate caused their enemies pain and death. They also used it to determine the fate of the sick by dropping a seed in a cup of stirred water; If the seed went around four times clockwise, the patient would recover, if it went around less than four times they would not.