The name Jack-in-the-Pulpit refers to the flowering structure of the plant. Jack is the cylindrical club-shaped structure (spadix) which bears minute flowers near the base and is enclosed in his pulpit which is a sheathing bracht (spathe). Jack's flowers may be either "male" flowers or "female" flowers, but not both. Jacks with male flowers produce only pollen. Those with female flowers produce scarlet berries. Jack can change his sex from year to year.

The plants have one or two large compound leaves composed of three leaflets. Those plants with two leaves are usually "female" while those with only one leaf are "male".

Family Araceae (Arum Family)