Northern Ontario Plant Database
Arisaema triphyllum (L.) Schott
Araceae (Arum Family)
General: A perennial herb, to 80 cm tall, growing from a thick tuber. Jack-in-the-pulpit tubers and leaves contain sharp crystals of calcium oxalate, which are physically and chemically irritating to mucous membranes, therefore, the plants should not be eaten.
Leaves: 1–2 per plant, basal, 3-lobed (trifoliate), pinnately-veined. Leaflets elliptic to lanceolate-ovate, 7.5–15 cm long; upper and lower surfaces green, smooth (glabrous); the leaflet bases tapering (cuneate), apices pointed (acute), margins entire.
Flowers: Bisexual or unisexual; each plant bearing a single inflorescence at the top of a stout stalk (peduncle). Flowers arranged at the base of club-shaped axis (spadix) and surrounded by a tubular bract (spathe), 2–4 cm tall; the outer surface of the spathe is marked with green and white vertical stripes, often striped with purplish-brown on the inside, the tip of the spathe arches over the tubular portion, forming a hood. Jack-in-the-pulpits are sequentially unisexual, producing female and male flowers in different years, some years only vegetative plants will be produced. The amount of food reserves accumulated the previous year apparently determines whether the plant will be vegetative or bear flowers, and whether male or female flowers will be produced. Flowers bloom in spring.
Fruit: Many ovoid, red berries, borne in clusters 2.5–7.5 cm tall. Fruits mature in summer.
Habitat and Range: Moist deciduous forests. Jack-in-the-pulpit is native to deciduous forests in eastern North America. In Ontario, it ranges to the north shore of Lake Superior.
Internet Images: The Arisaema triphyllum webpage from the Gallery of Connecticut Wildflowers, a website of the Connecticut Botanical Society.
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