Grafting and Cutting Propagation Techniques and Overwintering Management Tips for Golden False Acacia
The golden false acacia (Robinia pseudoacacia 'Frisia') has an umbrella-shaped crown. Its leaves are golden yellow in spring, turning yellow-green in summer and yellow-orange in autumn. In early summer it bears fragrant white flowers in pendulous racemes. It is a tree species with very high ornamental value. Below, the editor discusses the grafting and cutting propagation techniques for golden false acacia.
I. Propagation
1 Grafting
Select black locust (Robinia pseudoacacia) as the rootstock. Graft in spring when the sap is flowing, using cut grafting and cleft grafting. Select healthy, pest-free black locust rootstock with a diameter at breast height of 8-12 cm. First, cut the rootstock trunk at a height of 1.5-2.0 m, then use a sharp knife to make a cleft about 8 cm deep on the cross-section; the cleft must pass through the pith of the rootstock. Then insert the prepared wedge-shaped scion into the cleft, align the cambium layers of the rootstock and scion, and tie tightly. Depending on the thickness of the rootstock, 2-3 scions can be grafted to ensure the survival rate. After grafting, cover with white transparent plastic film and tie it tightly to reduce water evaporation from the scion, which also helps raise temperature, maintain humidity, and promote sprouting. When the scion sprouts and the new shoot reaches 3.5 cm, make a small opening in the film for ventilation. When the new shoot grows to 6 cm, remove the film.
2 Field Management
For grafted seedlings using the cut grafting method with film wrapping, after the scion sprouts and grows true leaves, cut a small opening in the film for ventilation; the opening should be small at first and gradually enlarged. When 2 true leaves have grown, remove the film entirely. For plants that failed to graft, re-graft promptly.
For bud-grafted seedlings, check the survival rate 15 days after bud grafting. If the bud is fresh and the petiole falls off at a touch, it indicates likely survival; otherwise, it may die, and dead ones should be re-grafted promptly. For plants whose grafted buds have survived, cut back the rootstock promptly; rootstock cutting is done in 2 stages.
Untie the binding 20 days after bud grafting survival and 25 days after cut grafting survival. Untying too early may cause the rootstock and scion to heal incompletely, while untying too late may cause constriction damage, affecting normal growth.
For surviving seedlings, promptly remove sprouts and root suckers from the rootstock. The golden false acacia has very strong sprouting ability, so multiple rounds of sprout removal are needed in production. For cut-grafted seedlings prone to wind breakage and bud-grafted seedlings with lateral growth, set up stakes and tie them for support and reinforcement.
Before grafting, water the seedbed thoroughly once. After grafting and healing, adjust watering according to weather conditions. Note that grafted seedlings whose bud grafts have not yet healed are sensitive to water at the graft union, so water cautiously. Be careful not to damage the buds and scions, especially the young shoots just sprouting from cut grafting and bud grafting.
3 Cutting Propagation
Cutting collection.In autumn during the plant's dormant period, select healthy, well-developed, pest-free 1-year-old plants with a diameter of 2-4 cm, collect branches, and refrigerate them promptly for storage. Before cutting, take out the stored branches, wash them clean with water, cut off the tips, and cut them into 20 cm long cuttings. Make a flat cut at the top 1.5 cm from a bud eye, and a flat cut at the bottom at the base of a lateral bud. The cuts should be flat.
Cutting treatment.Bundle the prepared cuttings into bundles of 25 each, and soak them in a 60-120 mg/L solution of ABT No. 1 rooting powder for 15 h. During soaking, only soak the basal portion of the cuttings, about 1/3 of the cutting length.
Bed preparation.In autumn, select a wind-sheltered, sunny, well-drained, flat site. Apply 1000 kg of decomposed farmyard manure per mu, deep plow, rake fine, and make beds. The bed width is 1.2 m, and the length depends on the plot. Water the bed thoroughly before planting.
Cutting time.The best time for cutting in Northeast China is mid-to-late April.
Transplanting.For transplanting grafted golden false acacia seedlings, the best season is spring; any time before the grafted seedlings sprout is suitable for planting. Transplant in areas with a relatively warm, humid climate and little wind. For large seedlings with a diameter at breast height of 5 cm or more, if used for landscaping, trunk cutting can be done before transplanting to facilitate shaping. When transplanting, note that grafted seedlings should be planted immediately after lifting to avoid prolonged exposure that causes physiological drought and death from excessive water loss. If long-distance transport of seedlings is necessary, soak the roots and maintain appropriate humidity during transport to ensure the seedlings do not suffer physiological drought. Large seedlings must be transplanted with a soil ball, and the root system must be protected. When planting, dig large holes, apply sufficient base fertilizer, fill with fine soil and firm it down. Water thoroughly once immediately after planting, and adjust watering thereafter according to weather conditions. During the vigorous growth period, strengthen water and fertilizer management, and apply 1 topdressing of nitrogen fertilizer at 50 kg per mu, preferably combined with 500 kg of decomposed farmyard manure for better results.
The above covers the grafting and cutting propagation techniques for golden false acacia. Below, let's look at overwintering management for golden false acacia.
II. The main management measures during the overwintering period are:
Watering for overwintering:The golden false acacia has a certain drought tolerance. Watering thoroughly once in late November can prevent winter drought, prevent new shoots from drying out, and also promote early sprouting in spring.
Loosening soil and fertilizing:In early winter, deep plow under the trees to loosen the soil and improve soil aeration. At the same time, apply 5-8 kg of decomposed organic fertilizer per tree along with the deep plowing.
Pruning and shaping: To maintain a beautiful tree shape, before winter, prune out overly dense branches, pest-damaged branches, dead branches, and useless branches that affect the tree shape.
Pest and disease control:The golden false acacia has few pests and diseases. In winter, lime-sulfur mixture paste can be used for whitewashing. Preparation ratio: one packet of crystalline lime-sulfur mixture, 3 jin of quicklime, 10 jin of clean water.
Black Locust Robinia pseudoacacia Linn. Black Locust Illustrated Guide: How to Grow Black Locust / How to Propagate Black Locust
Black Locust Fact SheetBlack Locust Robinia pseudoacacia Linn.
Black Locust Cultivation Methods and Precautions, Introduction to Black Locust
Black locust, also known as false acacia, is a deciduous tree in the Fabaceae family, genus Robinia. The bark is grayish-brown to dark brown, shallowly fissured to deeply longitudinally fissured, rarely smooth.
Black locust is native to North America and has now been widely introduced to Asia, Europe, and other regions. The bark of black locust is thick, dark, and heavily fissured; there is a pair of 1-2 mm long thorns at the base of the leaves; the flowers are white, fragrant, and borne in spike-like racemes; the fruit is a pod, with 4-10 seeds per pod. Black locust wood is hard, decay-resistant, burns slowly, and has high calorific value. Black locust flowers are edible. The honey produced from black locust flowers is very sweet, and honey yield is also high. Cultivated varieties include red-flowered black locust, golden false acacia, and others.
Morphological Characteristics of Black Locust
Black locust is a deciduous tree, 10-25 m tall; bark grayish-brown to dark brown, shallowly fissured to deeply longitudinally fissured, rarely smooth. Branchlets grayish-brown, with ridged angles when young, slightly pubescent, later glabrous; stipular spines present, up to 2 cm long; winter buds small, pubescent. Pinnately compound leaves 10-25 (-40) cm long; leaf rachis grooved on the upper side; leaflets 2-12 pairs, usually opposite, elliptical, oblong-elliptical, or ovate, 2-5 cm long, 1.5-2.2 cm wide, apex rounded, slightly emarginate, with a small mucro, base rounded to broadly cuneate, margin entire, upper surface green, lower surface grayish-green, pubescent when young, later becoming glabrous; petiolules 1-3 mm long; stipels bristle-like.
Racemes axillary, 10-20 cm long, pendulous, many-flowered, fragrant; bracts caducous; pedicels 7-8 mm long; calyx obliquely campanulate, 7-9 mm long, calyx teeth 5, triangular to ovate-triangular, densely pubescent; corolla white, all petals clawed, standard nearly circular, 16 mm long, about 19 mm wide, apex emarginate, base rounded, reflexed, with a yellow spot inside, wings obliquely obovate, nearly as long as the standard, about 16 mm long, with a rounded auricle on one side at the base, keel falcate, triangular, equal to or slightly shorter than the wings, connate along the anterior margin, apex obtuse-acuminate; stamens diadelphous, the one opposite the standard free; ovary linear, about 1.2 cm long, glabrous, stipe 2-3 mm long, style subulate, about 8 mm long, curved upward, hairy at the apex, stigma terminal.
Pods brown, or with reddish-brown markings, linear-oblong, 5-12 cm long, 1-1.3 (-1.7) cm wide, flat, apex curved upward, with a mucro, stipe short, with a narrow wing along the ventral suture; calyx persistent, seeds 2-15; seeds brown to dark brown, slightly glossy, sometimes with markings, nearly reniform, 5-6 mm long, about 3 mm wide, hilum circular, offset to one end. Flowering period April-June, fruiting period August-September.
Ecological Habits of Black Locust
Black locust is a temperate tree species, growing well in areas with an annual average temperature of 8°C-14°C and annual rainfall of 500-900 mm; especially in coastal areas with relatively high air humidity, it grows fast and develops straight, full trunks. It has poor wind resistance; black locust planted in wind tunnel openings is prone to wind breakage, windthrow, leaning, or crown deviation.
Black locust is very sensitive to moisture conditions. In places with too high a groundwater table and excessive moisture, it grows slowly and is prone to disease, causing root rot, shoot dieback, and even death. It has a certain drought tolerance. It prefers deep, fertile, loose, moist loam, sandy loam, sandy soil, or clay loam. It can grow normally on neutral soil, acidic soil, and saline-alkaline soil with a salt content below 0.3%, but grows poorly or even dies on waterlogged, poorly aerated clay. It is light-demanding and does not tolerate shade. Its sprouting ability and root sucker ability are both very strong.
Cultivation Techniques and Planting Methods for Black Locust
Site Selection, Land Preparation, and Fertilization
Black locust seedlings are sensitive to cold, waterlogging, and alkalinity, so the seedling nursery site should be selected as fertile sandy loam at a relatively high elevation with good drainage and irrigation. Soil salt content should be below 0.2%, and the groundwater table should be greater than 1 m. Choose irrigated land, or deep, flat, previously cultivated land. Do not raise seedlings in waterlogged lowlands or thin, poor mountain soils.
Black locust is not suitable for continuous cropping and can be rotated with poplar, pine, and other trees to prevent damping-off disease. Never raise seedlings on heavy clay soil. Land preparation requires intensive cultivation. Prepare land and fertilize in autumn, rake and harrow to conserve moisture in spring, and sow after irrigation in early May.
Field Management
In black locust seedling cultivation, mastering the seedlings' characteristics of drought tolerance, light preference, and intolerance of waterlogging is the key to ensuring seedling survival.
1. Irrigation
Do not irrigate from sowing until the seedlings emerge completely. After emergence, when soil moisture is moderate, loosen the soil and cultivate promptly to raise soil temperature and benefit germination. Irrigating too early, when soil moisture is excessive and soil temperature is low, can easily cause seedling stagnation or yellow-leaf disease. On the basis of repeated cultivation and soil loosening, the first irrigation can be given in early June, and thereafter under normal conditions, irrigate once every 20 d. After irrigation in early July, pause for a period to promote lignification of the seedlings and enhance overwintering ability. Give the final winter irrigation in late November.
2. Topdressing
After the black locust seedlings are thinned to a stand, carry out the first topdressing together with the first irrigation, applying 45-75 kg/hm^2 of urea. At the end of June, apply a compound fertilizer mainly of nitrogen and phosphorus twice along with irrigation, at 75-195 kg/hm^2. Stop fertilizing in early August. It is best to plow in winter and harrow in early spring, applying 3000-5000 jin of decomposed base fertilizer per mu. Spring land preparation should be done early, with deep plowing (over 25 cm), fine harrowing, and leveling. While preparing the land, mix 15 jin of black vitriol (ferrous sulfate) powder with 1 jin of 5% phoxim per mu, then mix in 40 times the amount of fine soil and spread it into the ground for soil sterilization.
3. Soil Loosening and Weeding
The seedling nursery should be cultivated promptly after irrigation or rain, keeping the soil loose and weed-free at all times.
4. Cold Protection and Overwintering
One- to two-year-old black locust seedlings are susceptible to autumn frost and spring dry wind damage, which causes the aboveground parts to dry up. Therefore, one-year-old seedlings should be dug out after autumn for autumn afforestation or overwintering heel-in, and provided for afforestation in the following spring.
5. Transplanting to Cultivate Large Seedlings
To cultivate large seedlings needed for roads, courtyards, urban landscaping, and similar uses, Yuanzhou District generally transplants from late April to early May. Transplanting density mainly depends on the target seedling cultivation specification and duration; generally, for four-year-old transplanted seedlings, a spacing of 50 cm x 100 cm is suitable. The longer the cultivation period, the greater the transplanting spacing should be. Black locust transplanting mostly uses hole planting. Before transplanting, cut off the aboveground parts and remove split or damaged roots. The root length should be maintained at 20-30 cm. Dip the seedling roots in slurry before planting. The planting depth should make the top of the root collar level with the ground surface. After transplanting, promptly carry out watering, topdressing, soil loosening, weeding, cold protection, and overwintering tending work. Especially for cut-back seedlings, do a good job of tip removal, bud removal, and branch pruning, selecting and retaining healthy, upright branches as the main trunk.
Black Locust Cultivation Methods and Afforestation Techniques
Afforestation Time
Black locust can be planted in both spring and autumn. Afforestation methods vary by location. In areas with many windy days in winter and spring and relatively dry, cold conditions, trunk-cut afforestation can be used in autumn or early spring; in places with a warm, humid climate and little wind, trunk-retained afforestation can be used in spring. Black locust sprouts late. In spring, the survival rate is higher when planting is done as the buds are about to open. The best afforestation time is from leaf fall in autumn to before the soil freezes.
Seedling Afforestation
For hilly and mountainous afforestation sites, the middle and lower parts of sunny slopes and semi-sunny slopes and low valley belts are suitable. The most suitable afforestation sites are: river floodplains with loamy interlayers, silty sand and fine sand sites with sandy loam to clay loam below 40-80 cm of the surface, deep-soil limestone and shale mountain sites, and gully slope lands on the Loess Plateau. However, wind tunnel sites, saline-alkaline land with a salt content above 0.3%, low-lying waterlogged land with a groundwater table above 0.5 m, overly dry coarse sand land, and heavy clay land are all unsuitable for planting black locust.
Afforestation density should be appropriate. For fast-growing high-yield forests, 110-200 trees per mu can be planted; for general timber forests, 220-330 trees; for soil and water conservation forests and fuelwood forests, more than 330 trees. When black locust is mixed with poplar, white elm (Ulmus pumila), tree of heaven (Ailanthus altissima), Chinese arborvitae (Platycladus orientalis), and false indigo (Amorpha fruticosa), tree growth is greater and pests and diseases are fewer. Belt-type mixed planting is preferable. In northern China, the maturity age is generally 20-30 years, and 40 years under good site conditions.
Taking advantage of black locust's strong root sucker and branch sprouting ability, mainly use healthy 1- to 2-year-old seedlings (ground diameter >= 0.8 cm, main root length >= 20 cm, well-developed and intact fibrous roots) for trunk-cut and root-buried planting. That is, when lifting seedlings, cut the aboveground part back to a height of 15-20 cm. Before planting, dip the seedling roots in mud slurry to retain moisture, then place them into prepared planting holes, straighten the seedlings, spread the roots, and fill soil in layers and firm it down. Spring planting does not require mounding soil, but autumn planting must mound soil for overwintering. Note that planting should not be too deep; generally, the planting depth should be 1-3 cm above the seedling root collar. Cover with a small mound of soil 15-20 cm high to bury the seedling trunk. The mounded soil should not be too deep; it should be level with the seedling or leave 1-3 cm of the seedling trunk exposed. Do not firm the mound; in spring, do not dig away the mound, so as to maintain soil moisture around the seedling.
Tending of Young Forests
In addition to normal weeding, soil loosening, and pest and disease control, young forest tending mainly involves removing suckers and buds, pruning branches, and removing tips, so as to cultivate a strong, straight main trunk and promote the formation of the trunk and crown.
Propagation Methods of Black Locust
Black locust is commonly propagated by sowing.
Sowing
Sowing black locust too early makes it prone to late frost damage, so sowing should be late rather than early, with the period around the "Grain Rain" solar term being most suitable. [5] Either drill sowing in beds or field-style sowing can be used. Generally, field-style seedling cultivation is used. First level the seedling land, then open furrows for drill sowing, with a row spacing of 30-40 cm and a furrow depth of 1.0-1.5 cm. The furrow bottom should be flat and the depth consistent. Spread the seeds evenly in the furrow, then promptly cover with 1-2 cm of soil and press lightly. From sowing to emergence takes 6-8 d, and the sowing rate is 60-90 kg/hm^2.
Seed Treatment
When black locust pods change from green to reddish-brown and the pod skin becomes hard and dry, they are mature. Harvest seeds at the proper time, sun-dry them, remove the pod skins, shriveled seeds, and debris to obtain pure seeds. The seed extraction rate from pods is 10-20%, the thousand-grain weight is about 20 g, and the germination rate is 80-90%.
Black locust seeds have a thick, hard seed coat, so germination must be promoted before sowing. Pour the seeds into 60-80°C hot water and stir thoroughly with a wooden stick. After 5-10 min, add cold water until the water temperature drops to 30-40°C. Then remove the impurities and bad seeds floating on the surface. Soak the good seeds for 24 h, then remove them. When slightly dry, sift out the hard seeds that have not swelled using a fine-mesh iron sieve, then repeat the hot-water soaking. Put the seeds that have absorbed water and swelled into a shallow basket, cover with a wet gunny sack, place in a sunny, warm spot, and rinse with warm water twice daily. After 4-5 d, when the seeds begin to germinate, they can be sown.
Pest and Disease Control of Black Locust
Black locust is harmed by many pests, including termites, leafhoppers, scale insects, black locust aphids, scarab beetles, longhorn beetles, black locust geometer moths, mulberry looper moths, and small stink bugs.
The black locust seed chalcid is the main pest of the seeds, with damage rates reaching over 80%. Pests and diseases of black locust seedlings include root maggots, weevils, aphids, and damping-off disease. When pests are found, spray with a 1500-fold dilution of 40% omethoate emulsion. For damping-off disease, at the early stage of onset, spray with a 300- to 400-fold dilution of 50% amobam to sterilize and protect the seedlings.
Variety Classification of Black Locust and Common Varieties
1. Umbrella black locust (variety) var. umbraculifera DC. in Moller's Deutsch. Gartn.-Zeit. 18: 630 (h). 1903.
Differs from the original variety in: branches dense and thornless, crown nearly spherical, rarely flowering and fruiting.
Cultivated in the Dalian and Qingdao areas.
2. Tower black locust (variety) var. pyramidalis (Pepin) Schneid. Ill. Handb. Laubh. 2: 83. 1907.——R. pyramidalis Pepin in Rev. Hort. ser. 2, 4: 240. 1845.
Differs from the original variety in: branches upright, thornless, crown cylindrical.
Seen in garden cultivation.
Variety Classification
Existing black locust varieties can be broadly grouped by use into the following categories:
(1) Timber tree species;
(2) Landscape and greening tree species;
(3) Fodder forest tree species;
(4) Honey-source forest tree species;
(5) Energy forest or shelterbelt tree species;
(6) Fertilizer tree species.
Of course, there is often overlap among these categories, and other classification methods are also possible.
In recent years, domestic forestry science and technology personnel have also selected many new black locust varieties suitable for landscaping. They are:
1. Straight-trunk black locust (Robinia pseudoacacia 'Bessouiana'), with a straight, upright trunk and yellow-white flowers;
2. Golden false acacia (R. pseudoacacia 'Frisia'), a medium-height tree with golden yellow leaves;
3. Twisted-branch black locust (R. pseudoacacia 'Tortuosa'), with twisted branches, also known as knobby black locust;
4. Columnar black locust (R. pseudoacacia 'Pyramidalis'), with fine lateral branches, a cylindrical crown, and white flowers;
5. Globe-crown black locust (R. pseudoacacia 'Umbraculifera'), with a spherical crown, becoming umbrella-shaped in old age;
6. Tortoise-shell bark black locust (R. pseudoacacia 'Stricta'), with bark peeling in a tortoise-shell pattern, yellow-brown;
7. "Red-flowered" black locust (R. decaisneana L.): corolla papilionaceous, purplish-red. Cultivated in Nanjing, Beijing, Dalian, and Shenyang.
8. Thornless black locust (R. pseudoacacia Var. inermis DC): crown open, tree shape broom-like, branches stiff and without stipular spines. Cultivated in Qingdao, Beijing, and Dalian. Propagated by cuttings, mostly used as street trees.
9. Small-leaf black locust (R. pseudoacacia Var. microphylla): leaflets 1-3 cm long, 0.5-1.5 cm wide. Compound leaves gradually become smaller from the top to the base. Pods 2.5-4.5 cm long, less than 1 cm wide. Cultivated in Zaozhuang City, Shandong.
10. 'Arrow-shaft' black locust (R. 'upright' L.): trunk upright, branches fine and sparse. Planted in Jiaonan County, Qingdao City.
11. "Yellow-leaf" black locust (R. 'yellow' L.): selected in Guangrao County, Dongying City, Shandong. Leaves remain yellow-green year-round. Propagated by division or grafting.
12. Globe black locust: crown spherical to ovate, branches fine and dense, nearly thornless or with very small, soft thorns. Small tree. Does not flower or flowers very rarely.
13. Pink-flowered black locust: flowers slightly tinged with pink.
Distribution Range of Black Locust
Black locust is native to the United States and is cultivated from 23°-46° N latitude and 86°-124° E longitude. It was introduced to Europe and Africa in the 17th century.
China introduced it from Europe to Qingdao for cultivation at the end of the 18th century, and it is now widely planted throughout China. In the Yellow River basin and Huai River basin, it is mostly planted in concentrated contiguous stands and grows vigorously. On the North China Plain, its vertical distribution is between 400-1200 m. It is cultivated in Gansu, Qinghai, Inner Mongolia, **, Shanxi, Shaanxi, Hebei, Henan, Shandong, and other provinces (regions).
Uses and Value of Black Locust
Black locust wood is hard and heavy, decay-resistant and wear-resistant, and is suitable for sleepers, vehicles, construction, mine props, and many other uses; it grows fast and has strong sprouting ability, making it a fast-growing fuelwood tree species; it is also an excellent honey-source plant. [1]
Black locust grows rapidly. Its wood is tough, fine-grained, elastic, water-resistant, and decay-resistant, making it an important fast-growing timber tree species. It can be used for construction, sleepers, vehicles, and farm tools; the leaves contain crude protein and can be used as feed; the flowers are an excellent honey-source plant, and the seeds are pressed for oil used as raw material for soap and paint.
Industrial Value
In the food industry, locust bean gum is often compounded with other food gums and used as a thickener, water-retention agent, binder, and gelling agent. Compounded with carrageenan, it can form elastic jelly, whereas carrageenan alone can only produce brittle jelly. Compounded with agar, it can significantly increase the rupture strength of the gel. Compounded with alginate and potassium chloride, it is widely used as a composite gelling agent for canned foods. Compounded with carrageenan and CMC, it is a good ice cream stabilizer. It can also be used as a water-retention agent in dairy products and frozen dairy desserts to improve mouthfeel and prevent ice crystal formation.
Landscape Uses of Black Locust
Black locust has a shallow but well-developed root system, is prone to windthrow, and is highly adaptable, making it an excellent tree species for sand fixation and soil conservation. In the Huang-Huai River basin of the North China Plain, there are relatively large contiguous plantations, while in other areas it is mostly planted as scattered greenery around homes and sporadically, and is commonly seen as a street tree.
The black locust has a tall, broad crown and bright green foliage. When it blooms, the green and white set each other off, elegant and fragrant. It can serve as a street tree or shade tree in courtyards. It is a pioneer species for greening industrial and mining areas and for afforesting barren hills and wastelands. It is relatively resistant to sulfur dioxide, chlorine gas, and photochemical smog, and also has a strong ability to absorb lead vapor. Its roots bear root nodules, which also help improve soil fertility. After the leaves fall in winter, the branches are sparse and grow upward, much like a silhouette, with a form that carries the charm of traditional Chinese painting.
The dietary therapy or medicinal value of black locust
The medical information and health dietary therapy information on Huahua Network is for reference only and cannot be used as a basis for diagnosis or medical treatment. Any health issue should be consulted with professional medical personnel, and the treatment of any disease should follow a doctor's advice.
The ultimate flower-guarding mission: to love yourself, start from reality and strictly follow a doctor's advice. For illness, do not be careless, do not delay, do not give up hope, face it bravely, warm the silent world with love, and care for the flower field in your heart with your heart.
Medicinal value
Functions and indications
Stop bleeding. Mainly indicated for large intestinal bleeding, hemoptysis, hematemesis, and profuse uterine bleeding in women.
Toxicity
If black locust young sprouts and young leaves are mistakenly used as a supplementary food, poisoning may occur due to factors such as the body being allergic to black locust, improper cooking, excessive consumption, or sunlight exposure after eating. Twenty-three cases have been reported, with poisoning mostly occurring between 2 and 20 days after eating. The manifestations include swelling of the face and hands, localized stabbing pain, burning pain or distending pain, itching, and general weakness. Rescue method: decoct and take 2 liang of edible vinegar and 4 liang of dandelion, temporarily avoid sunlight exposure, and symptoms can be relieved within 2 to 3 days.
Identification
Microscopic identification
Powder characteristics: pale yellow-green.
① On the fragment of the petal, the anticlinal walls of the upper epidermal cells are wavy-curved, slightly curved, or straight; the cells of the claw part are longitudinally elongated, and the outer walls of the cells have obvious cuticular striations; the lower epidermal cells resemble the upper epidermis.
② The upper epidermal cells of the calyx are polygonal; the cells at the base of the calyx are longitudinally elongated, and non-glandular hairs are sometimes visible; the lower epidermal cells resemble the upper epidermis, but non-glandular hairs are densely arranged, and stomata are also seen.
③ Non-glandular hairs can be seen everywhere; the complete ones are 131-413 μm long, straight or slightly curved, mostly 2-celled, with the basal cell short and small and the terminal cell long.
④ The parenchyma cells in the calyx can be observed, and some cells contain yellow-brown or light reddish-purple substances.
⑤ The inner and outer epidermal cells of the filament are narrowly rectangular.
⑥ Fragments of the outer epidermis of the ovary are sometimes visible; the cells are narrow and small, 20-39 μm long and 9-15 μm wide.
⑦ Pollen grains are 30-35 μm in diameter, with smooth walls.
⑧ Vessels are small and often spiral.
⑨ Calcium oxalate prismatic crystals may be observed, 4-10 μm long.
Physicochemical identification
Thin-layer chromatography: spot the methanol solution of the sample on a silica gel G thin layer, develop with n-butanol-glacial acetic acid-water (4:1:1), then spray with a 1% aluminum trichloride (ALCL3) ethanol solution, and observe the fluorescent spots under ultraviolet light. The Rf of robinin = 0.46; if the developing solvent is changed to (4:1:2), Rf = 0.54; when isopropanol-water (7.6:2.4) is used as the developing solvent, Rf = 20.70.
Chemical composition
The flowers contain canavanine, tannins, flavonoids, and ricin.
The nectar contains 0.37% sugar and various amino acids such as aspartic acid, glutamic acid, histidine, arginine, lysine, ornithine, leucine, phenylalanine, valine, tyrosine, proline, and threonine, with contents of 0.002-4.786 mg% of the dry weight of the nectar.
The leaves contain acaciin (C28H32O13·4H2O), acacetin (C16H12O5), trisaccharide glycosides, robinin (C33H40O19), tannins, and so on.
The immature seeds and their outer hard coat contain canavanine. The seeds contain phytohemagglutinin. The fatty acid composition of the seed oil is: linoleic acid 53.18%, oleic acid 24.26%, linolenic acid 12.04%, palmitic acid 4.72%, arachidic acid 3.31%, stearic acid 2.35%, and trace amounts of docosanoic acid and tetracosanoic acid.
The bark is toxic and contains toxic proteins and toxic glycoside components. The heartwood contains robinetin, dihydrorobinetin, β-dihydroxybenzoic acid, methyl β-dihydroxybenzoate, 4,2',4'-trihydroxychalcone, liquiritigenin, butein, butin, and 3,4,5,2',4'-pentahydroxychalcone.
Cultural background of black locust and appreciation of a beautiful essay - The Black Locust Tree
Seeing the locust tree in the backyard again, the scars on the tree made me think of an experience. When it comes to the trees in my hometown, there are not many kinds, but the one that left the deepest impression on me is the black locust. It can be said that the locust tree is a particularly common tree in our village, almost seen everywhere.
I especially like the flowers the locust tree blooms in spring; the flowers are so pure white and so fragrant. The leaves of the locust tree are also very special, oval-shaped, with no pointed part at all. Moreover, the leaflets do not grow on the branches, but grow on both sides of the slender petiole strips extending from the branches. On each side of a petiole there are about 7-10 leaflets, so if picked together with the petiole, they form clusters. If the leaves are pulled off and put in the mouth, they can still make a whistling sound, and the taste of the leaves is not bitter.
I remember that when we were children, we picked black locust flowers in spring, were not idle in summer either and picked leaves to build shade shelters, and in autumn carved tree holes in the trunks of the locust trees. Thinking about it now, we really were a bit too mischievous.
As for the shade shelter, of course it was not for people to live in, because the area was too small. After all, this shelter was only made of leaves. As for who could live in it, of course it could only be my toy figure. At that time I also thought to myself that although I built the shelter with leaves myself, I was not fortunate enough to enjoy it. It was the toy figure who was blessed! In fact, that toy figure at the time was the miniature of my childhood soul. Although I could only sit on the ground and look at the top of this leaf shelter, my heart had already moved in along with the toy figure. Looking at the toy figure lying motionless under the shelter in a posture that never changed, my heart was fantasizing: if this green shelter before my eyes, as in that fairy tale, became bigger, what would it be like? What would happen? But all of this could only ever become a dream.
Speaking of carving tree holes in autumn, perhaps carving tree holes is not exactly an environmentally friendly thing. But for a mischievous child, he did not understand what environmental protection was. What he considered was his soul (the toy figure). In autumn, the leaves turned yellow, and a shade shelter could no longer be built. The so-called miniature of himself, his "soul," had no place to stay. Now that winter was coming, he was afraid that the "miniature of his soul" (the toy figure) would freeze, so with his two little hands he picked up an iron hammer and an iron chisel respectively, and under the blowing of the autumn wind the chisel began working on the old trunk. Before long the bark was chiseled open, but the living tree was indestructible, and no matter how he chiseled, it was only very shallow, yet the mischievous child did not give up and frantically chiseled the trunk. At this time a white liquid flowed out from the tree's wound, but the mischievous child had no pity at all that the tree also had to get through winter, and how could he know that the sap flowing down was the tree's nourishment for winter, and also the tree's blood! In spring the locust tree offered its flowers, and in summer it offered its leaves too. Yet the mischievous child still did not stop the iron hammer and iron chisel in his hands for even a moment. Only when he was exhausted did he put down the weapons in his hands and lower his head. Because the mischievous child had limited strength, the tree hole was not completed. He lowered his head not for this tree but for his "soul" (the toy figure). The mischievous child looked at the toy figure and expressed regret, perhaps blaming himself, because in the end he had failed to let his soul move into the tree hole.
Now seeing this tree again, the so-called mischievous child has also grown into an adult. But the scar left on the tree is still there, only slightly higher than the original height.
The flower language of black locust
The flower language of black locust: friendship; another saying is secret love.
Black locust pictures
Key points of autumn nursery stock pruning, maintenance, and transplanting
Autumn is the season of harvest, and it is also one of the important seasons for nursery stock maintenance and management. With the gradual development of nursery stock maintenance techniques, practitioners have more and more work to do in autumn. Autumn maintenance can better solve the problems of short spring maintenance time, spring drought, and labor shortages. In addition to pruning and shaping, cold protection, and pest and disease control, nowadays the propagation and transplanting and planting of many nursery stocks are also often carried out in autumn.
Pruning and shaping. The constantly dropping temperature makes the growth vigor of nursery stock weaker and weaker, and finally they enter a dormant state. Deciduous tree species also begin to shed leaves during this process. Pruning at this stage causes relatively less damage to the tree body. At the same time, for the shaping of deciduous tree species, after the leaves fall, the form of the tree body can be presented relatively clearly before the workers, making shaping work easier. In addition, branch bending, which can ensure better growth of nursery stock, can be carried out all year round, but the effect is best in autumn. The reason is that compared with branch bending in spring, vigorous branches will not sprout on the back of the plant, and in autumn the branches are soft, so bending is not easy to split. After bending, the return flow of nutrients is blocked, which improves the accumulation of nutrients in various parts of the tree body and is beneficial to flower bud differentiation.
Cold protection. Although cold protection is the focus of winter work, if preparations can be made in advance in autumn, it will achieve twice the result with half the effort for winter cold protection. Especially in northern China, where winters are cold, for nursery stock moved from the south to the north, newly transplanted nursery stock, and non-cold-resistant flowering trees and shrubs cultivated in the open field, cold protection must be carried out to avoid low-temperature damage, and it can improve the cold resistance of plants to a certain extent.
Pest and disease control. As autumn and winter arrive, the plants in the nursery gradually enter a dormant state, the leaves fall off, and the occurrence of pests and diseases is relatively reduced. However, many overwintering pests lay eggs in autumn, seeking suitable places for the survival and development of the next generation, and diseases also scatter everywhere in the nursery along with fallen leaves. If cleaning work can be done well at this time and prevention carried out, it will be much simpler and more efficient than getting anxious and angry after pests and diseases occur in large numbers.
Transplanting and planting. In autumn the temperature gradually drops, the amount of water transpiration is relatively low, and the moisture content in the soil is relatively stable. When the soil temperature is still high, the roots of cold-resistant tree species planted in autumn can still resume growth, so the survival rate is relatively high. Autumn transplanting can begin when the upper part of the nursery stock stops growing and the petioles of deciduous trees form an abscission layer and fall off or are manually removed. Because at this time the root system has not yet stopped its activity, and after transplanting it is beneficial to the recovery of root wounds.
Propagation. Most people generally propagate nursery stock in spring, but studies have shown that some varieties also have a very high survival rate when propagated in autumn, including both trees such as lacebark pine, ginkgo, and black locust, and shrubs such as Japanese barberry and golden-leaf privet. For example, ginkgo can be propagated in autumn by the bare-branch cutting method, and many fir varieties also have a very high survival rate when propagated by cuttings in autumn. In addition, using overcast and rainy days in autumn to carry out the transplanting and planting of seedlings, grafted seedlings, and cutting seedlings is also an important means of improving efficiency and ensuring the survival rate.