Famous for its dense fragrant inflorescences, white acacia has no botanical affinity with plants of the same name. It is more correct to call a tree a robinia. This representative of the legume family only resembles subtropical shrubs by the structure of the leaves and the shape of the fruits.
Botanical Description
Robinia pseudoacacia - Robinia pseudoacacia or pseudoacacia came to Europe from North America. Due to its high adaptability, it took root in all regions with a temperate climate, and has long been perceived in the Old World as a local plant. This is a large tree with a height of 20–25 m and a trunk width of 60–90 cm. The bark of a young shoot is gray-brown, smooth. It darkens with age, thickens, interrupted by deep longitudinal cracks. The shoots are densely branched, bare, light olive in color, with small, barely distinguishable glance buds. The crown is spreading, openwork, rounded in the upper part, downwards forms several separate wide tiers.
The roots of white acacia have many branches, penetrate deep into and several meters wide. At the ends of the shoots there are points sensitive to nitrogen compounds.
The leaves are light, bluish-green, pinnate, composed of 7–21 elongated lobes, almost sitting on the central petioles. Plates 3-4 cm long, about 1.5 cm wide, with rounded or notched apexes. The back of the leaves has a matte silver tint.
Flowers are greenish-white or cream in color, 10–17 mm in size, bell-shaped, collected in drooping carpal inflorescences 15–20 cm long. In warm regions, the flowering period begins in May, temperate and continental in June or July.
Fruits: flat hard beans 5-12 cm long with a brownish-brown peel. Ripen in late September. Inside contains from 3 to 15 smooth bud-shaped seeds, light green or spotty.
Robinia is light-loving, unpretentious to the composition of soils, able to tolerate prolonged drought. In mixed forests, it adjoins pine, maple or oak. It grows very quickly, rising to a height of 60–90 cm per year. It is easily restored by root shoots after cutting.
Medicinal properties
Bark, greens and white acacia flowers are medicinal natural raw materials. They contain glycosides and a number of other chemically active substances:
- tannins;
- alkaloids;
- salicylic acid esters;
- flavonoids;
- phytosterol;
- essential oils;
- tannins;
- vitamin C;
- vitamins A and E.
Preparations based on this raw material have a strong choleretic, expectorant, hemostatic, anti-inflammatory, antispasmodic, antipyretic effect.
The seeds and other parts of the white acacia contain the poisonous alkaloid robinin. A large amount of it when ingested causes severe intoxication, therefore, it is necessary to handle the tree carefully. Poisoning can occur both in the collection of flowers, fruits and bark, and in the harvesting of wood. Its main symptoms: severe nausea, headache, physical weakness.
Application
Robinia is considered an invasive species, because, quickly exploring new places, it violates the natural ecosystem of the region, crowding out weaker species and expanding its range. Despite this, they do not seek to completely exterminate the white acacia, given its medicinal and other useful properties.
Wood
The robinia massif belongs to sound species. It has a light greenish-brown or grayish-yellow shiny surface with a contrasting pattern of tree rings and core rays. It is a strong solid material, superior in density to oak and ash. In the drying process, it is capricious, but in its finished form acquires plasticity, biostability and wear resistance. It lends itself well to all types of carpentry, bends, holds all types of fasteners, and is impregnated with varnishes and paints.
White acacia is suitable for external and internal construction work: it is used when installing earth piles, erecting supports in mines, railway sleepers, temporary bridges, fences. Furniture is made from it, finishing panels for wall covering, parquet, hatchets, handles of agricultural implements.
Traditional medicine and homeopathy
In folk medicine, flowers, bark and young twigs of white acacia are used to prepare medicinal decoctions and tinctures for influenza, pneumonia, rheumatic and muscle pain, neuralgia, diseases of the kidneys, bladder, liver, stomach, intestines. Alcohol tincture of the bark is used to increase acidity, with hypokinetic cholecystitis.
Outwardly, an infusion of bark is used to disinfect cuts, abscesses, abrasions, and heal boils and ulcers.
Robinin alkaloid, which saturated parts of the plant, is toxic in high concentration. Like many natural toxins, it is in demand in homeopathy and serves as a raw material for the manufacture of multidirectional drugs: from headache, joint pain and toothache, violations of the female menstrual cycle, colitis, pancreatitis, vegetovascular dystonia, neurosis, insomnia, and exhaustion.
Landscaping
Pseudo-action robinia is planted along the slopes of ravines, embankments of railways, along the edges of abandoned quarries and farmland. Thanks to the powerful ramified root system, these trees perfectly strengthen the soil crumbling in the places of slopes. High spreading crowns create reliable wind protection, preventing soil erosion.
Robinia are good in parks, city squares and gardens. They are decorative, not afraid of gas and smoky air. In regions with severe winters, they rarely grow above 10 m, often branching, forming shrubby forms. In the adjoining territories they can be planted singly or create hedges.
Chemical industry and pharmacology
Yellow and blue pigments are isolated from the bark and leaves of the plant. They are used for the production of dyes and tanning leathers.
Fragrant essential oil of flowers is a popular fragrance in pharmacology, perfumery and cosmetics.
White Acacia Honey
Robinia is a valuable honey plant. During flowering, fragrant brushes attract bees from all around. One large adult tree per season can produce up to 15 kg of nectar.
Acacia honey is considered more beneficial than other types. It contains less organic acids and pollen, therefore it is approved for use by people with high acidity of the stomach and those who are prone to allergies. By its antimicrobial and anti-inflammatory qualities, this honey is superior to other varieties.
Another important feature - it remains liquid for a long time.. If other species crystallize in 2-3 months after harvesting, the acacia retains transparency for almost two years. Sugar proportions in it are different: fructose predominates over glucose almost 1.5 times. This allows the product to be used for cosmetic and therapeutic procedures in which heating is unacceptable and a liquid substance is necessary.
The taste of honey is thin, with a subtle floral aroma and a bitter aftertaste.
Landing
To place the robinia, you need to choose flat or elevated, well-lit areas with a low level of groundwater. Fertility of the soil does not matter much, more important is its friability and alkaline reaction. This plant is not afraid of saline soils. It is recommended to add lime, dolomite flour, wood ash to acidic ones. Heavy soils - dilute with sand.
When choosing places for planting, you need to retreat away from the walls of buildings, fruit trees and vegetable beds. Over time, the roots of acacia grow in breadth and drown all the others. The presence of communications: cables, pipelines is a big obstacle for a robinia.
It is advisable to carry out work in early May. Too early or fall plantings can be affected by extreme cold. The earth around the future seedling is dug up, removing grass. A pit is prepared with a depth and a width twice that of the volume of its roots. With insufficient soil friability, a thick layer of stone drainage is laid at the bottom. When planting a tree, the root neck is not buried. At the end of work, a bucket of water is poured under the barrel. It is recommended to mulch adjacent soil with a 7–8-cm layer of high peat.
Care Tips
Robinia are not capricious and resistant to adverse weather conditions, so they don’t cause any trouble taking care of themselves.
Watering plants is required only in the first two seasons and only in drought. Mature trees develop powerful roots and extract moisture from the soil. Excess water will damage them, causing rot.
No need to feed white acacia. It itself enriches the soil with nitrogen compounds, and for rapid growth it converts substances in the soil. Trees begin to bloom 3-4 years after planting. If the formation of inflorescences is delayed or they are very rare, in the spring it is recommended to apply potash fertilizers to the soil. They can be scattered around the trunk in a dry form, and then slightly moisten the soil. Weed grass under the trunks should be removed. There should be no turf over the roots of the robinia.
For winter, young seedlings need to be insulated. The roots are covered with a thick layer of peat or leaves, and the crowns in severe frosts are wrapped in a thin burlap. Freezing branches in spring can be cut short without regrets - this stimulates the further growth of trees. After 4-5 years, the frost resistance of acacia improves, it is no longer necessary to cover it.
Formative haircut is welcome. Shoots can be shortened to half the length. This is required in March or April, before flowering begins.
Breeding
White acacia can be diluted with seeds, layering or root offspring. In the first case, the material is pre-scarified, cutting a dense shell, and embedded in the soil to a depth of 2-3 cm. Sprouts appear after 10-15 days and in the first season reach a height of 60-80 cm.
Siblings growing up to 40–50 cm in the summer are carefully dug up and simply transferred to new places.
Varietal specimens can be propagated by air layering, bending strong long branches to the ground. In the place of contact with the soil, they are incised and buried. During the warm season, cuttings are rooted, the next year they are cut off and transplanted.
Diseases and Pests
If the regime of moistening the trees is organized correctly, they are not threatened by diseases. This is facilitated by the presence in the greenery and bark of toxic compounds that inhibit the activity of microbes.
Of the parasites of the white acacia, a pseudoscutum and a sawfly threaten. They suck juices from young herbs. To protect crowns from pests, it is useful to regularly treat them with infusions of hemlock, black bleached, soda solution. With massive lesions, insecticides are more effective: Karbofos, Actor and others.
In favorable conditions, with proper care, robinia live up to 100 years, and with the threat of death, plants are easily restored from seeds or by vegetative methods.