Many different forms of this species have been described by botanists. Although these morphological forms may be recognizable in the field, distinguishing these differences in herbarium specimens is often difficult, and there is much overlap occurs in expression of the characteristics supposedly defining infraspecific taxa. Numerous intermediate forms exist, including putative hybrid populations between the subspecies. Given these problems and the sympatric ranges of the 'subspecies' recognized by previous workers, Arisaema triphyllum is treated here as one highly variable species[].

Common Name: Jack In The Pulpit

General Information

Arisaema triphyllum is a herbaceous perennial plant growing from a tuber that is usually renewed seasonally. The tuber also produces some tubercles around its base - these become separated from the old tuber at the end of the season, growing on in subsequent years to form new plants[].
The plant was used by Native N. Americans as a food and medicine, though is probably little used nowadays due to its potential toxicity. It is sometimes grown as an ornamental.

Known Hazards

The plant contains calcium oxylate crystals. These cause an extremely unpleasant sensation similar to needles being stuck into the mouth and tongue if they are eaten but they are easily neutralized by thoroughly drying or cooking the plant or by steeping it in water.

Botanical References

,

Range

Central and Eastern N. America - Manitoba to Nova Scotia, south to Texas and Florida

Habitat

Wet woods, bogs and swamps[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.60 m
Pollinators	Flies
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Prefers a cool peaty soil in the bog garden, woodland garden or a sheltered border in semi-shade[, , ]. Prefers a loamy or peaty soil and will tolerate a sunny position if the soil is moist but not water-logged and the position is not too hot or exposed[, ].
Tubers should be planted about 10cm deep[]. Only plant out full sized tubers and mulch them with organic matter in the winter[]. Plants need protection from slugs[].
This species hybridizes in the wild with Arisaema draconitum. These plants do not produce mature fruits but do reproduce vegetatively[].
Most species in this genus are dioecious, but they are sometimes monoecious and can also change sex from year to year.
The plant is paradioecious. The sex depends on nutrition and is therefore variable from one year to another[]. Smaller plants produce only staminate flowers, whilst larger plants produce either staminate and pistillate flowers simultaneously or pistillate flowers only. Changes in gender expression are directly correlated with size and are also influenced by the environment in which the plants are growing. Reversions in phenotypic gender have been experimentally induced by such factors as removing leaf area or changing soil nutrient levels[].

Edible Uses

Tuber - it must be thoroughly dried or cooked before being eaten[, , , , , ]. The roots can be cut into very thin slices and allowed to dry for several months, after which they are eaten like potato chips, crumbled to make a cereal or ground into a cocoa-flavoured powder for making biscuits, cakes etc[, ]. They can also be pounded into a powder, this is thern left to dry for several weeks when it becomes safe to use[]. The root is up to 5cm long and 2cm wide[]. Caution is advised, see the notes above on toxicity.

Medicinal

The root is acrid, antiseptic, diaphoretic, expectorant, irritant and stimulant[, , , , ].
The root was applied as a poultice on headaches, scrofulous sores, rheumatism, boils, abscesses and ringworm[, ]. A decoction of the root has been used as a wash for sore eyes[].
The root was used as a contraceptive by the N. American Indians. One teaspoonful of the dried powdered root in cold water was said to prevent conception for a week whilst two teaspoonfuls in hot water was said to induce permanent sterility[].
The root is harvested in early spring and dried for later use[]. The fresh root is considered to be too dangerous and intensely acrid to use, whilst the dried roots become inactive, so fresh, partially dried roots are used[].
Due to the potentially toxic nature of this plant, it should only be used internally under the supervision of a qualified practitioner[].

Other Uses

A starch obtained from the roots is used as a stiffener for clothes[]. It is very harsh to the hands, causing blisters and swellings[].

The seeds have been used in rattles[].

Propagation

Seed - best sown as soon as it is ripe in a shady position in a cold frame[]. Stored seed remains viable for at least a year and can be sown in spring in the greenhouse but it will probably require a period of cold stratification. Germination usually takes place in 1 - 6 months at 15°c[]. When large enough to handle, prick the seedlings out into individual pots and grow them on in light shade in the greenhouse for at least a coupe of years until the corms are more than 20mm in diameter. Plant out into their permanent positions whilst they are dormant.
Division of tubers when the plant dies down in late summer.