This section is from the book "A Guide To The Poisonous Plants And Weed Seeds Of Canada And The Northern United States", by Robert Boyd Thomson, H. B. Sifton. Also available from Amazon: A guide to the poisonous plants and weed seeds of Canada and the northern United States.
Arisaema triphyllum (L.) Schott.
Other Common Names: Indian or Wild Turnip, Three-leaved Arum.
The plant is acrid, especially its corm, which is very poisonous, having been used, according to Pammel, as insect poison. It is claimed that boiling or baking reduces the acridity. Animals do not eat it.
A native of North America, it is common in low, moist woods as far west as the prairies. The large pale-green spathe, streaked with brown or purple, arches over the spadix in the form of an old-fashioned pulpit. On the narrowed base of the spadix or "Jack" small flowers are borne, either staminate or pistillate as the case may be. The fruit is bright red. The leaves are compound of three smooth oval leaflets with entire margins.