Horticulture/Arisaema triphyllum

Description
The leaves are trifoliate, with groups of three leaves growing together at the top of a long stem; each leaflet is 8–15 cm long and 3–7 cm broad. Plants are sometimes confused with Poison-ivy especially before the flowers appear or non-flowering plants. The inflorescences are shaped irregularly and grow to a length of up to 8 cm long. They are greenish-yellow with purple or brownish stripes. The spathe, known in this plant as "the pulpit" wraps around and covers over and contain a spadix ("Jack"), covered with tiny flowers of both sexes. The flowers are unisexual, in small plants most if not all the flowers are male, as plants age and grow larger the spadix produces more female flowers. This species flowers from April to June. The fruit are smooth, shiny green, 1 cm wide berries clustered on the thickened spadix. The fruits ripen in late summer and fall, turning a bright red color before the plants go dormant. Each berry produces 1 to 5 seeds typically, the seeds are white to light tan in color, rounded, often with flattened edges and a short sharp point at the top and a rounded bottom surface. If the seeds are freed from the berry they will germinate the next spring, producing a plant with a single rounded leaf. Seedlings need three or more years of growth before they become large enough to flower.

It is hardy to USDA plant hardiness zone 3.

Chemical composition and medicinal uses
The plant contains calcium oxalate crystals in all parts, and because of this consumption of the raw plant material results in a powerful burning sensation. It can cause irritation of the mouth and digestive system, and on rare occasions the swelling of the mouth and throat may be severe enough to affect breathing.

If the plant is properly dried or cooked it can be eaten as a root vegetable.

A preparation of the root was reported to have been used by Native Americans as a treatment for sore eyes. Preparations were also made to treat rheumatism, bronchitis, and snakebites, as well as to induce sterility.

History and folklore
Some accounts of the Meskwaki Indians state that they would chop the herb's root into meat and leave it for their enemies to find. The taste would not be detectable, but consuming the meat reportedly caused their enemies sufficient pain to be fatal. They also used it to determine the fate of the sick by dropping a seed in a cup of water. If the seed went around four times clockwise, the patient would recover, otherwise they would not.

Warning
According to the website DrKoop.com, the oxalic acid and asparagine in jack in the pulpit are poisonous if ingested. Care should also be taken to avoid confusion with poison ivy, which has 3 leaflets somewhat similar in appearance.