Arisaema is a large and diverse genus of perennial flowering plants in the family Araceae, order Alismatales. The genus comprises 224 accepted species (POWO) distributed across temperate and tropical regions of Asia, Africa, and North America, with the greatest concentration of species found in China, Japan, and the Himalayas. In common parlance, Asian species are often called cobra lilies, while the familiar North American species are known as jack-in-the-pulpit — both names allude to the genus's most distinctive feature: an erect, club-shaped spadix rising from a hood-like spathe that arches protectively over it.
Plants grow from underground corms or tubers and produce bold compound leaves, often with a glossy surface. The inflorescence — spathe and spadix together — ranges from subtly striped to dramatically flared and elongated depending on species. After flowering, female plants develop dense clusters of showy red or orange berries that persist into autumn. The genus name is derived from Greek, combining words for "arum" and "red," a reference to the red-blotched foliage characteristic of several species.
One of the most remarkable biological traits of Arisaema is sequential hermaphroditism: plants typically function as males when young and resource-poor, transitioning to female or even hermaphroditic status as they accumulate energy over time. This sex-switching can occur multiple times during a plant's lifespan of more than 20 years and is governed by nutritional status and, in part, genetic factors. Closest phylogenetic relatives include the genera Pinellia and Typhonium, and a 2016 study resolved 15 distinct sections within the genus.
All parts of Arisaema plants contain calcium oxalate crystals, which cause intense irritation and swelling of the mouth and throat if consumed raw. This toxicity is effectively neutralized by thorough drying, prolonged soaking, or cooking. Several species carry ethnobotanical significance: the dried corms have been used medicinally by Native American peoples and feature prominently in traditional Chinese medicine (as Tian Nan Xing), where they are prescribed for respiratory conditions, as antispasmodics, and for a range of other ailments.
Etymology
The genus name Arisaema combines two Greek roots: a word for "arum" (referring to the Arum family to which the genus belongs) and one meaning "red," alluding to the red-blotched leaves found on several species. The common names jack-in-the-pulpit (North America) and cobra lily (Asia) both describe the appearance of the inflorescence — a central spadix standing upright within an arching, hood-like spathe, evoking either a preacher in a pulpit or a rearing cobra.
Distribution
Arisaema has a broad but discontinuous distribution spanning three continents. According to POWO, the native range extends from eastern DR Congo through Ethiopia and Tanzania in Africa, across the Arabian Peninsula through South and Southeast Asia (including the Himalayas, China, Japan, and Korea) to Sakhalin Island and Malesia, and separately from central and eastern Canada south through the eastern United States to Mexico. The genus reaches its greatest species diversity in China, Japan, and the Himalayan region. In North America, species such as Arisaema triphyllum typically inhabit moist deciduous woodlands and seasonally flooded low woodlands. Asian species occupy deciduous and mixed forests, streamsides, and montane habitats, with PFAF recording altitudinal ranges around 50–200 m for some East Asian taxa.
Ecology
Arisaema species are woodland perennials adapted to dappled to deep shade and moist, humus-rich soils. One of the genus's most notable ecological features is sequential hermaphroditism: plants begin reproductive life as males and switch to female or hermaphroditic function as they accumulate energy reserves, with individual plants capable of multiple sex changes across a lifespan exceeding 20 years. This phenomenon is governed by nutritional status and genetic factors. Plants emerge from corms each spring, set fruit as dense clusters of red berries attractive to birds and small mammals, and die back underground in winter. North American species favour seasonally flooded low woodland and are deer and rabbit resistant. All parts contain calcium oxalate crystals, which deter most herbivores; the crystals are neutralized by cooking or drying.
Cultivation
Arisaema species thrive in shaded garden positions with moist, humus-rich, well-drained soil of acid to neutral pH — conditions that mimic their native woodland habitat. Corms should be planted 3–4 cm deep (some sources recommend up to 15 cm for larger species); deeper planting provides protection from frost. Most species tolerate heavy shade and require minimal maintenance once established. Some species are sensitive to winter moisture, which can cause corm rot; in those cases, raised beds or sharp drainage is advisable, supplemented by a winter mulch of organic matter. Plants are generally deer and rabbit resistant. All plant parts are toxic if consumed raw due to calcium oxalate crystals, so care should be taken when handling the sap or fruit pulp, which can cause mild contact dermatitis.
Propagation
Arisaema can be propagated by seed or by vegetative division. Seeds sown in spring or autumn germinate slowly (1–6 months at 15°C) and seedlings require 3–5 years before reaching flowering size. Division of cormlets in spring (or of tubers in late summer when dormant) is a faster method, as established clumps naturally produce offsets over time. Colonies spread gradually through cormlet multiplication.
Cultural Uses
Arisaema has a long history of human use across its range. In North America, several Indigenous peoples used Arisaema triphyllum ritually and medicinally. In East Asia, the dried and processed corm of several species — known collectively as Tian Nan Xing in traditional Chinese medicine — is a classical remedy valued for its effects on the respiratory system. It is prescribed to treat coughs with profuse phlegm, as an antispasmodic for conditions such as tetanus and epilepsy, and has been applied externally to treat skin complaints. Modern analyses have confirmed antibacterial and antifungal activity. Additional folk uses include treatments for rheumatism, stomachache, liver complaints, and urinary tract disorders. Raw consumption is dangerous due to calcium oxalate toxicity; medicinal preparations require thorough drying or processing. Edibility, where practised, involves prolonged soaking and boiling of the corm, which is 6–7 cm in diameter in some species.
Conservation
No genus-wide IUCN conservation assessment is available for Arisaema, and the genus is not listed in the IUCN Global Invasive Species Database. At the regional level, certain Arisaema species in Minnesota floodplain habitats are designated as species of special concern due to habitat loss and land use change. The genus's woodland habitat — moist, shaded, and often seasonally flooded — is broadly susceptible to drainage, forest clearance, and agricultural encroachment across its range.
Taxonomy
Arisaema Mart. was first described by Carl Friedrich Philipp von Martius and published in Flora 14(2): 459 in 1831. It is placed in the family Araceae, order Alismatales, subfamily Aroideae, tribe Arisaemateae. The genus is accepted by Plants of the World Online (POWO/Kew) with 224 species, while GBIF records 305 total descendants and Wikipedia cites approximately 212 accepted species as of February 2025. Seven heterotypic synonyms are recognized by POWO, including Dochafa, Flagellarisaema, Heteroarisaema, Muricauda, Pleuriarum, and Ringentiarum. Closest phylogenetic relatives are Pinellia and Typhonium. A 2016 molecular phylogenetic study resolved 15 distinct sections within the genus, each with a designated type species. The IPNI identifier for the genus is urn:lsid:ipni.org:names:328148-2.
