Arisaema verrucosum utile (Hook.f. ex Schott) Pradhan
Arisaema utile is a herbaceous perennial plant growing from a tuber that is usually renewed seasonally. 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 sometimes harvested from the wild for local use as a food.
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.
E. Asia - southern China, Pakistan, India, Nepal, northern Myanmar
Forest openings at elevations of 1,800 - 3,700 metres in Nepal[
]. The margins of evergreen Tsuga forests, thickets; at elevations from 2,800 - 3,100 metres[
Prefers a cool peaty soil in the bog garden, 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 hot or exposed[
Tubers should be planted about 10cm deep[
]. Only plant out full sized tubers and mulch them with organic matter in the winter[
]. Plants need protection from slugs[
Closely related to Arisaema griffithii[
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[
Leaves and flowering spathes - cooked as a potherb[
The tubers of several species in this genus are recorded as being edible after treatment. We have no specific information for this species, but the depressed-globose tuber is 3 - 10cm in diameter[
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.