Aralia is a subtropical thermophilic plant; its genus unites several dozen species. Most of them are small deciduous trees, shrubs with beautiful carved crowns or tall perennial grasses. Due to the presence of potent substances, the leaves and bark of these representatives of the flora are used in pharmacology and traditional medicine.
Botanical Description
Grassy aralia have hard, thick stems up to 50-60 cm tall, with many spines. Shrubs and trees usually grow up to 5–7 m, occasionally up to 10 m. The trunks are straight, thin, covered with gray bark and dotted with thorns. Twigs and leaf petioles are also prickly.
The root system is superficial, with many branched shoots occurring at a depth of up to 60 cm. The lateral branches are short, concentrated closer to the apex, the lower parts of the plants remain bare, which makes them look like palm trees. The similarity is enhanced by large, complex structure of leaves: twice or thrice pinnate, alternately located on short petioles. Leaf blades are bright green, broadly egg-shaped or heart-shaped, with pointed tips.
Aralia blooms late - in the middle of summer or in August. The flowers are bisexual, small, fragrant, white or cream in color, collected in rare umbrella inflorescences. Fruits - Dark purple or black round berries with several flat, hard seeds ripen in autumn.
Prevalence
The natural habitat of species of Aralia is the territory with a tropical climate, subtropics with a sufficient level of moisture. These are Central and South America, the southern states of the USA, regions of Southeast Asia, the Sunda Islands, Japan, and China. Small ranges are found in the temperate zones of Asia and North America.
In Russia, aralia is found in the nature of the Far East: Khabarovsk Territory, Amur Region, Primorye, Sakhalin and the Kuril Islands. It grows in broad-leaved forests, at the edges, in valleys, along river banks, in alpine regions.
Kinds
The genus Aralia has more than fifty species distributed on several continents. Cultivated varieties include several of them:
- Chinese In nature, grows in southern China, in Vietnam and Malaysia. It is a thorny branched shrub or compact tree up to 8 m tall. The leaves are light green, up to 50 cm in size, the plates are pointed, with serrated edges, pubescent from the back. Inflorescences are white paniculate, fruits about 3 mm in size.
- Continental. Far Eastern species: shrub about 1 m high with a spherical carved crown and large paniculate inflorescences. The leaves are complex-ply, up to 40-50 cm long, smooth on the upper side, slightly pubescent on the back. The shape of the leaf lobes is heart-shaped. The panicles of the inflorescences are light cream, decorative, up to 30 cm in size. The flowering period begins in August. Black and blue fruits with a diameter of about 5 mm ripen in late September.
- Heart-shaped. Large grassy shrub, common in China, Korea, Japan and Sakhalin. The stems are bare, hard. The leaves are very large, pinnate, composed of several lobes, elongated up to 15–20 cm. The apical plates are wider, heart-shaped. The upper part of the leaves is dark green, the lower one is noticeably lighter. Inflorescences are apical, white, up to 45 cm long, sparse, consist of the main and several accessory umbrellas. Fruits - small black berries 3-4 mm in size.
- Aralia is high or Manchurian. It is found throughout the Russian Far East, in China and Japan. A small tree 1.5–5 m high with a spherical crown. Leaves are twice pinnate, reaching a length of 90–100 cm. Lobes dark green, elliptical, pointed, 10–15 cm in size. Inflorescences are yellowish or white, 25–40 cm in diameter, consist of several umbrellas. The fruits are black, up to 5 mm in diameter, ripen in late September or October. In Russia, high aralia is called the Devil's Tree.
- Bristled Aralia. North American variety, perennial drought tolerant shrub 70–150 cm high. Stems with thin spiky thorns, creeping roots. The leaves are twice complex pinnate, 20–25 cm long, elongated, elliptical lobes, 2 × 9 cm in size. The inflorescences are yellowish, rare, paniculate, 7–10 cm in diameter, on thin peduncles. Fruits are purple-black, spherical, about 10 mm in size.
- Aralia is prickly. Distributed in southeast North America. One of the largest species: a moisture-loving tree or bush up to 12–15 m high with a trunk width of 20–30 cm. All parts of the plant are strewn with long, strong spikes. The leaves are dark green, bluish below, very large, up to 1 m long, twice and thrice complex pinnate. Frames are wedge-shaped, with pointed tips, 7–10 cm. Inflorescences are white, with a diameter of 25–30 cm. Fruits are achenes of black color 6–8 mm in size.
Application
Umbrella and rounded carved crowns of aralia with large inflorescences and bright dark fruits look very picturesque in single or group plantings, fitting into any landscape. Plants are planted in gardens as tapeworms, compositions or hedges. During flowering, bushes and trees become excellent honey plants.
The roots, leaves and bark of some species are used as raw materials in the pharmaceutical industry. They contain:
- alkaloids;
- essential oils;
- glycosides;
- organic acids;
- triterpene saponins.
For medicinal purposes, they often use high or bristly aralia - trees and bushes not younger than 5 years of age. Roots and bark are harvested in October or early spring. Leaves - in the summer, during flowering and some time after it.
Healing properties
Aralia preparations have an exciting, cardiotonic, hypoglycemic, gonadotropic effect, stimulate respiration, and improve blood circulation. Tinctures from the roots and leaves of the plant are used for vascular atherosclerosis, hypotension, depression, neurosis, asthenovegetative syndrome, concussion, meningitis, and a decrease in potency in men.
Due to the strong action of alkaloids and glycosides, aralia must be used in strictly prescribed dosages. Excessive use of drugs causes intoxication and impaired activity of the central nervous system.
Landing
For cultivation for decorative and medicinal purposes, they often use Manchu aralia (aralia mandshurica). This is the most common variety, it has good frost resistance, tolerates a long-term temperature drop to –30 ° C and can grow in temperate climates.
For planting, choose sunny or semi-shaded areas with loose neutral, well-moistened soil. The acidity level should not exceed 6 pH. When choosing a place, the ability to grow rapidly and the presence of sharp spikes are taken into account. The bushes are arranged so that there is no need to touch them when moving around the garden.
Before planting, the soil is fertilized with humus and mineral fertilizing is applied: 30–40 g of nitrophosphate.
Aralia seeds can be sown in autumn directly in open ground at a constant place to a depth of 2-3 cm. Having passed stratification in winter, they quickly germinate with the onset of heat. The distance between seedlings should be 80-100 cm. Extra seedlings dive in the summer.
For planting vegetative material - cuttings or offspring - prepare holes with a depth of about 40 cm. At the bottom, 15 cm of a mixture of peat and humus are poured. After falling asleep, the soil is abundantly moistened and mulched with sawdust, straw, dry leaves or grass. You can use foam or cardboard chips.
Care
The main requirements for aralia care are: frequent hydration, regular top dressing and keeping the soil clean. Watering plants in the first years of growth is necessary 2-3 times a week, pouring 10-12 liters of water for each instance. It is impossible to swamp the soil around the roots, so it is optimal to use small-jet watering cans. Adult aralia can be watered once a week.
During the growing season, 30–40 g of complex mineral fertilizer is applied under the roots. It is advisable to do this in the spring. Several times it is useful to pour the soil with a liquid solution of rotted cow manure, compost. The last top dressing is carried out in October after fruit ripening.
In the first years of seedlings' life, the aerial part during cold winters can freeze heavily. In March, damaged shoots are shortened, the dead are cut off completely. Over the summer, shrubs grow again. After 3-4 years, the plants are sufficiently hardened and cease to suffer from cold. In order to protect young plantings, it is recommended to cover the root system and crowns for the winter: pour a thick layer of mulch, use a thin burlap, and rake up snow in winter.
It is recommended to start forming pruning when the bushes reach the age of 4–5 years.
Diseases and Pests
Aralia successfully resists fungal pathologies. Due to the presence of its own bactericidal substances, it practically does not get sick. Pest resistance in a plant is much lower. Parasites that are attracted by juicy greens:
- wireworm: very difficult to exterminate, wood ash powder, dry mustard help get rid of it;
- bear: insects damage the roots and bark of aralia, to combat them, it is necessary to use insecticides, set traps, put poisoned bait;
- slugs: these pests that eat the leaves are peeled from the shoots manually, for prevention, the greens are sprayed with a soap or soda solution.
Inspect the branches and trunks of aralia in search of possible parasites or damage should be every 3-4 days.
Breeding
Aralia are bred by sowing seeds or basal processes. Healthy seed remains viable for two years. Store it in a dark, dry place at a temperature not exceeding 20 ° C.
The processes appear at the roots of adult plants. In the spring or summer, subordinate shoots 20-30 cm long are gently dug and disconnected from the donor. These are ready-made seedlings that already have their own roots and are ready for placement in new places.
Aralia is rarely propagated by cuttings.. Reasons: a small number of strong shoots of sufficient length. The segments should be at least 1 cm thick and about 15 cm in length, have 2-3 growth buds. Root them in boxes with the soil mixture at room temperature or immediately plant them in open ground.
Under favorable conditions, aralia blooms and begins to bear fruit in the 6-7 year of life. The northern palm tree has been living for at least 25 years.