Arisaema jacquemontii

Family: Araceae

What it is like

Arisaema jacquemontii is a PERENNIAL growing to 0.6 m (2ft) by 0.3 m (1ft in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from June to July. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Flies. The plant is not self-fertile. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.6

Where it is found

Shrubberies and rocky slopes in upper forest and lower alpine zones in the drier areas of the Himalayas, 2400 - 4000 metres.

E. Asia - Himalayas - Afghanistan to S.E. Tibet.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

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.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 0

Other

Rating:

How it is grown

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. This is probably the hardiest of the Himalayan species and should succeed outdoors in a suitable position in many parts of the country. Only plant out full sized tubers and mulch them with organic matter in the winter. Plants need protection from slugs. Closely related to A. wardii. Most species in this genus are dioecious, but they are sometimes monoecious and can also change sex from year to year.

Propagating it: 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.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge; not Deep Shade;

Habit: Perennial

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium

Shade: Full shade, semi-shade, no shade

Moisture: Moist

Things to keep in mind

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.

Its other names

Local names

Synonyms

A. cornutum. A. exile.