By Liliana Usvat
Blog 249-365
Common name: Black Locust
Latin name: Robinia pseudoacacia
Blog 249-365
Common name: Black Locust
Latin name: Robinia pseudoacacia
Very few nitrogen fixing trees are temperate, and very few of these are legumes. The genus Robinia, with four species native to temperate regions of North America, is noteworthy for an ability to tolerate severe frosts.
Robinia pseudoacacia L., or black locust (family Leguminosae, subfamily Papilionoideae), is among the few leguminous NFTs adapted to frost-prone areas. It is also adaptable to environmental extremes such as drought, air pollutants, and high light intensities (Hanover 1989). Rapid growth, dense wood, and N fixing ability make it ideal for colonizing degraded sites.
Robinia pseudoacacia will tolerate almost any soil conditions; it will be happy in acid, neutral or alkaline pH levels, in loam, sand, clay or chalk and facing any aspect so long as it is given a sheltered location.
Description
Black locust is a medium-sized tree reaching 1535 m in height and 0.3-1.0 m in diameter. Long (2045 cm) pinnate leaves consist of 5-33 small, oval, alternate leaflets. Sharp spines are found at the nodes of young branches but are rare on mature wood.
The smooth bark becomes reddishbrown and deeply furrowed with age. White to pink, fragrant flowers in 10-25 cm long, hanging racemes appear in early summer soon after the leaves. The closed flowers require bees to force petals open for cross-pollination.
The small pods contain 4-8 hard-coated seeds which can persist in the soil for many years. Seed crops occur every 1-2 years beginning at age 3; pods open on the tree in winter and early spring.
Propagation Reforestation
They can be propagated, with difficulty, from hardwood cuttings (15-30 cm long and 1-2 cm diameter) collected in winter or early spring. The tree responds well to tissue culture and has been mass propagated by this method. In nursery culture black locust is either direct seeded or root sections (5-8 cm long) planted.
The species has one of the highest net photosynthetic rates among woody plants. Black locust grows rapidly, especially when young. Trees can reach 3 m tall in one growing season and average 0.5-1.5 m height and 0.2-2 cm diameter growth per year. Trees attained 12 m ht in 10 yrs and 20 m ht in 25 yrs in Kashmir (Singh 1982), and 26 m ht and 27 cm diameter in 40 yrs
Uses
Honey:
Bees harvest Robinia nectar to produce a honey regarded as one of the world's finest. Tree improvement specifically for late flowering and high nectar sugar content is ongoing in Hungary and the US.
Other:
The tree is used extensively to rehabilitate surface mine tailings in the US. In Hungary. A dense growth habit makes black locust suitable for windbreaks, a use most common in China.
Black locust may even prove useful for alley cropping in temperate climates. Researchers at the Rodale Research Center in Pennsylvania are experimenting with intercropping black locust with vegetables.
Numerous reports indicate the beneficial effect of this NFT to associated plants through improved soil fertility. Mixed plantings of black locust and conifers, however, can lead to reduced growth or death of the slower growing conifers because of shading and over-topping.
Medicinal use
- Dried leaves are helpful in treatment of wounds caused by burns.
- It acts as a pain reliever.
- Used internally, it calms stomach burns,
- and is usually recommended to individuals who suffer from hyperacid gastritis and
- distensions.
- It is helpful in easing digestion.
- As a good emollient and expectorant,
- Black Locust is excellent in treatments of asthma and bronchitis.
- Black Locust has a sedating and calming effect, and
- could be very useful in cases of headaches and
- stress.
- Infusion added to baths can help young children who suffer from insomnia.
- Flower powder is used in cases of gastritis, duodenal and gastric ulcer.
