The berries produced by Arisaema triphyllum are usually eaten by birds as well as mammals. The scientific name of this plant, Arisaema triphyllum, comes from the Greek words (arum) and (aima) which mean red. This refers to the leaves of this species which are sometimes red. In addition, this plant is poisonous to humans.
Best grown in fertile, medium to wet soil in part shade to full shade. Needs constantly moist soil rich in organic matter. Does poorly in heavy clay soils. May be grown from seed, but takes five years for plant to flower.
Arisaema triphyllum, commonly called Jack-in-the-pulpit, is a spring woodland wildflower usually growing 1- 2′ tall. Flower structure consists of the spadix (Jack) which is an erect spike containing numerous, tiny, green to purple flowers and the sheath-like spathe (pulpit) which encases the lower part of the spadix and then opens to form a hood extending over the top of the spadix. The outside of the spathe is usually green or purple and the inside is usually striped purple and greenish white, though considerable color variations exist. Two large green, compound, long-petioled leaves (1-1.5′ long), divided into three leaflets each, emanate upward from a single stalk and provide umbrella-like shade to the flower. The fleshy stalk and leaves lend an almost tropical aura to the plant. Flowering plants initially produce only male flowers, but become hermaphroditic as they further age (male flowers on upper part of spadix and female on lower part). Most plants in a colony will vanish by mid-summer (become dormant), but the mature, hermaphroditic flowering plant will produce a cluster of red berries in mid to late summer which becomes visible as the spathe withers. Roots contain calcium oxalate (same chemical as in Diffenbachia or dumb cane) and are poisonous.
Genus name comes from Greek words aris meaning “arum” and aima meaning “red”, in reference to the red-blotched leaves found on some species.
Specific epithet means three-leaved.
No serious insect or disease problems.
Best left undisturbed in the shady woodland garden, wild garden or native plant garden
Arisaema triphyllum, the Jack-in-the-pulpit, is a species of flowering plant in the arum family Araceae. It is a member of the Arisaema triphyllum complex, a group of four or five closely related taxa in eastern North America. The specific name triphyllum means “three-leaved”, a characteristic feature of the species, which is also referred to as Indian turnip, bog onion, and brown dragon.
Used without qualification, the name Arisaema triphyllum is ambiguous. For clarity, the qualified name Arisaema triphyllum sensu stricto (abbreviated s.s.) refers to the species while Arisaema triphyllum sensu lato refers to the species complex. The latter includes the species (Arisaema triphyllum) among its members.
Arisaema triphyllum sensu lato is wide-ranging across eastern North America, from Nova Scotia to Manitoba in eastern Canada, and from Texas to Florida in the southern United States. It is common throughout most of its range.
Plant in the Allegheny National Forest, Pennsylvania, USA
Closer view of flower, showing detail of spathe
The Arisaema triphyllum complex includes four closely-related species: Arisaema pusillum, Arisaema stewardsonii, Arisaema quinatum, and Arisaema triphyllum sensu stricto. A fifth species (Arisaema acuminatum) is sometimes included but its validity is controversial.
Arisaema triphyllum sensu lato is a herbaceous, perennial, flowering plant growing from a corm. It typically grows up to two feet tall, but populations in Georgia and Florida are known to reach almost twice that height. It has 1 or 2 leaves, each with three leaflets (triphyllum). Occasionally the lateral leaflets will be two-parted or lobed, giving the appearance of five leaflets per leaf. One species (A. quinatum) typically has five pseudo-leaflets per leaf.
The small, inconspicuous flowers of Jack-in-the-pulpit are borne on a fleshy, spike-like inflorescence called a spadix (“Jack”), which is enclosed (or nearly enclosed) by a large, sometimes colorful bract called a spathe (“pulpit”). The flowers are clustered around the base of the spadix inside the spathe. A sterile spadix appendix protrudes from the mouth of the spathe tube. The appendix is covered by the leafy tip of the spathe, referred to as the spathe hood (or spathe lamina). The lip along the mouth of the spathe tube, used as a landing platform for winged insects, is called the spathe flange.
The inflorescence can be male (with male flowers only), bisexual (with both male and female flowers), or female (with female flowers only). In a small plant, most if not all of the flowers are male. As the plant matures and grows larger, the spadix produces female flowers as well as male flowers. The transition from male to female continues until eventually the plant produces only female flowers. This is an example of dichogamy, a rare phenomenon in flowering plants. Due to this sex-change lifecycle, this species is sometimes called colloquialy as Jack or Jill in the pulpit    or Jill-in-the-pulpit.  
The unripe fruits are smooth, shiny green berries (each 1 cm wide) clustered around the thickened spadix. Fruits ripen in the late summer and early fall, turning a conspicuous bright red color. Each berry typically produces 1–5 seeds, which are white to light tan in color, rounded, often with flattened edges and a short sharp point at the top. If the seeds are freed from the berry, they will germinate the next spring, producing seedlings each with a single rounded leaf. A seedling needs three or more years of growth before it becomes mature enough to flower.
Arisaema pusillum, Arisaema stewardsonii, and Arisaema quinatum are diploid with 28 chromosomes. Arisaema triphyllum s.s. is predominantly tetraploid with 56 chromosomes but plants otherwise indistinguishable from typical A. triphyllum occasionally have 28 chromosomes. Two such plants were found in Cayuga County, New York in the 1940s. The evolutionary origin of the tetraploids is unknown.