Arisaema spp.—Jack in the pulpit; Indian Turnip
FAMILY: Araceae—the Arum Family
The Araceae are primarily tropical in distribution. Seven genera, all but one containing a single species, are encountered in the flora of Pennsylvania. Members of the family are best known as house plants in our region (e.g. Monstera, Philodendron, Anthurium, Dieffenbachia, Pothos, Scindapsus, Calla, Caladium, and Aglaonema). The family is characterized by plants with milky, watery or sharply pungent sap and calcium oxalate crystals in the tissue. The flowers are often unisexual. In some species, both male and female flowers occur in the same inforescence. In other species, the plants bear either all male (staminate) or all female (pistillate) flowers. Regardless, the flowers are generally small and aggregated in a cluster on a thick, fleshy spike called a spadix. The spike is often surrounded or subtended by a bract or leaflike structure, the spathe, which may be colored and flowerlike.
PHENOLOGY: The species of Arisaema flower from late April to late June.
DISTRIBUTION: The plants are most commonly encountered in rich woods, thickets, moist areas, swamps, bogs, and swales.
PLANT CHARACTERISTICS: In Arisaema the flowers occur at the base of the spadix; the spathe is green or purple-brown, often with light-green lines. Flowers: small, in clusters, without a perianth; staminate flowers: composed of 2-5 subsessile anthers, opening at the apex; pistillate flowers: consisting of a l-celled ovary and a broad stigmatic surface; fruit: a cluster of globose berries, red when mature, each containing 1-3 seeds; leaves: long-petioled, compound; corms: very acrid,.
POISONOUS PARTS: Berries presumably are not poisonous but taste peppery. Leaves and roots (acrid sap) can cause contact dermatitis. Roots (corm) when eaten in quantity can cause severe burning in the throat and mouth. Inflammation can cause choking.
SYMPTOMS: Nausea, vomiting, diarrhea, and inflammation of the mucous membrane upon ingestion.
POISONOUS PRINCIPLES: The toxicosis is produced by mechanical piercing of the mucous membranes by calcium oxalate crytals, possibly a protein or asparagine, and other unknown toxins.
CONFUSED TAXA: There is some disagreement among botanists concerning the division of the genus Arisaema into species. Current research supports two species: A. triphyllum (L.) Schott. (with 3 varieties) and A. Dracontium (L.) Schott. The two are differentiated by the number of leaflets per leaf and the nature of the spadix. In A. triphyllum there are 3 leaflets and a blunt spadix covered by the spathe, whereas A. Dracontium leaves are composed of 7 to 13 leaflets and the spadix is long, protruding from the spathe,
SPECIES OF ANIMALS AFFECTED: Mortality in humans and livestock has not been reported in the literature; however, death has been induced experimentally in animal feeding studies.
TREATMENT: Dermatitis - (4); (23); ingestion - (11a)(b); (4); (6); (9); (10); (26),
OF INTEREST: Skunk cabbage, Symplocarpus foetidus (L ) Nutt, also a member of the Araceae, contains calcium oxalate crystals. An overdose of the underground parts causes nausea, vomiting, vertigo, disturbed vision, and headaches. Both Arisaema and Symplocarpus have been utilized medicinally. The Pawnee Indians pulverized the dried corms and dusted the powder on the head and temples to relieve aches. Symplocarpus "roots'' have been dried and powdered to give the aged relief from asthma and catarrh. Some cultivated, poisonous plants of this family are discussed under the entries Dieffenbachia and Philodendron.