Arisaema

Family Araceae. Name: from the Greek "aris", a diminutive of "aron" - arum, and "sema" - sign, characteristic.

Description: a perennial plant belonging to one of the most ancient and remarkable families of flowering plants, the Araceae. Many of them, with original leaf shapes and coloration and extraordinarily beautiful inflorescences, have great ornamental value and have long been cultivated (calla, anthurium). Most Araceae grow in the tropics and subtropics; only a few species occur in the temperate zone, which are of certain interest for amateur horticulture.

Arisaema are perennial herbaceous plants with a small (2 - 6 cm in diameter) tuber and rather thick roots that are located around the renewal bud. The inflorescence is a spadix. The decorative part is the spathe of the inflorescence of unusual shape: funnel-shaped at the base, then straight, then arching into a hood. The bright fruits of Arisaema are also interesting. There are about 150 species of Arisaema, occurring mainly in East Asia. In our country there are four species found in the valley mixed and deciduous forests of the south of the Far East. Despite their origin, Arisaema can grow in the central part of Russia. In particular, they do quite well in the open ground of the Botanical Garden in St. Petersburg.

Arisaema can be divided by type:

tall "palm-like", for example: A.ciliatum and its varieties, A. consanguineum, A. erubescens, A. heterophyllum and A. multisectum

low-growing, for example: A. amurense and its forms, A. candidissimum, A. griffithii, A. ringens, A. triphyllum, A. japonicum, A. franchetianum, A. sikokianum

But the generally accepted classification is by the regions of occurrence:

1.China:
A. candidissimum.
A. ciliatum and its varieties
A. consanguineum
A. dahaiense
A. erubescens
A. franchetianum
A. lobatum
A. multisectum
2. Japan, Korea, USA:
A. amurense
A. amurense f. robustus
A. japonicum
A. heterophyllum
A. ringens
A. sikokianum
A. triphyllum
A. urashima = A. thunbergii ssp. urashima
3. India, Bhutan, Nepal (mainly the Himalayas):
A. griffithii (it can also be attributed to China - it grows in Tibet)

Location: a sunny or slightly shaded, well-drained spot. They like to grow near bodies of water.

Soil: Arisaema are quite hardy plants and can grow in one place for many years without transplanting. They are generally not demanding about soil, but grow better and produce a greater number of tuber offsets on loose, well-drained fertile soils with sufficient moisture.

Care: in winter plantings should be covered with a layer of leaves; this especially applies to the three-leaved and Japanese Arisaema. In almost all Arisaema the tubers are apple-shaped and moisture tends to accumulate in the depression at the base of the stem. During autumn rains or a rainy summer this area (the stem base) can rot, so it is recommended to slightly hill up (earth up) Arisaema. Hilling prevents water from getting to the base of the stem and the upper part of the tuber, where there is usually a depression (around the stem) - and this is the "weak" spot in many species. It is from the stem base and the adjacent area of the tuber that bacterial rot often starts. Excess water in a rainy autumn provokes this disease. Hilling tall species also helps to better secure the stem of Arisaema in the ground so the plant does not rock. This is especially desirable when Arisaema are planted in open, wind-exposed sites and their stems are tossed from side to side by strong winds. Warm-loving Arisaema are taken into a refrigerator for the winter, covered with dry sawdust.

Propagation: digging up and transplanting Arisaema can be done throughout the autumn. The tuber is planted at a depth of 15 cm. The distance between plants is 15 cm. They are easily propagated vegetatively by the "offsets" formed on the tuber. Division of the tuber is possible after the end of the growing season. Seeds dry out quickly and lose viability. Therefore, after collection they are packed in moist moss and stored in a refrigerator. But it is better to sow freshly collected seeds in August; then seedlings appear in the spring of the following year. Seedlings bloom in 3-5 years. Self-seeding is common in cultivation.

To accelerate germination, it is necessary to wash the seeds from the fleshy coverings after they ripen and stratify for 1 month in warmth, then for at least 2 months in cold. Germinate at 20-25°C. Pricked-out seedlings are not transplanted until the end of the growing season (mid-summer), after which they are planted in the open ground at a depth of 3-5 cm. When growing seedlings it is necessary to maintain even soil moisture. If allowed to dry out, plants may go into dormancy prematurely underdeveloped and die.

Use: Arisaema are very interesting plants with an exotic appearance. They are recommended for planting in amateur gardens near ponds, as well as in shaded rockeries.

Companions: planted with ferns, Symplocarpus, Lysichiton, Saxifraga stolonifera (Manchurian saxifrage).