Common Name:

General Information

Arisaema jacquemontii is a herbaceous perennial plant growing from a tuber that is usually renewed seasonally. The plant produces one or two leaves 20 - 52cm tall and a flowering stem up to 50cm tall, 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 is harvested from the wild for local use as a food. It is often grown as an ornamental in gardens[].
With a large range in remote high elevation areas Arisaema jacquemontii warrants no particular need for conservation attention. It occurs in protected areas and does not appear to be threatened at present. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

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

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Range

Asia - Afghanistan, Pakistan, northern and southern India, Nepal, Bangladesh, China

Habitat

Shrubberies and rocky slopes in upper forest and lower alpine zones in drier areas of the Himalayas; at elevations from 2,400 - 4,000 metres[]. Coniferous forests, open grassy places in forests, Juniperus or Rhododendron thickets, forest margins[].

Properties

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

Cultivation Details

This is probably the hardiest of the Himalayan species and should succeed outdoors in a suitable position in many parts of the temperate zone[].
Prefers a cool moist peaty soil in the bog, 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 exposed[, ].
Only plant out full sized tubers and mulch them with organic matter in the winter[]. Plants need protection from slugs[].
This species is losely related to Arisaema wardii[].
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

Root - cooked[]. Used in the same ways as potatoes[]. The tubers are 12 - 30mm in diameter[]. The root must be thoroughly cooked or dried before use, see the notes above on toxicity.

Leaves - dried[]. The leaves are fermented before being eaten in Nepal[]. Some caution is advised, see the notes above on toxicity.

Medicinal

None known

Other Uses

None known

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.