Robinia pseudoacacia, commonly known in its native territory as black locust,[3] is a medium-sized hardwood deciduous tree, belonging to the tribe Robinieae of the legume family Fabaceae.

It is native to a few small areas of the United States, but it has been widely planted and naturalized elsewhere in temperate North America,[4] Europe, Southern Africa[5] and Asia and is considered an invasive species in some areas, such as the temperate east coast of Australia where the cultivar "Frisia" (Golden Robinia) was widely planted as a street tree before being classed as a weed.

[9] When young, the branches are at first coated with white silvery down; this soon disappears, and they become pale green and afterward reddish or greenish brown.

[9] The flowers themselves are cream-white (rarely pink or purple) with a pale yellow blotch in the center and imperfectly papilionaceous in shape.

Black locust leaves contain flavone glycosides characterised by spectroscopic and chemical methods as the 7-O-β-ᴅ-glucuronopyranosyl-(1→2)[α-ʟ-rhamnopyranosyl-(1→6)]-β-ᴅ-glucopyranosides of acacetin (5,7-dihydroxy-4′-methoxyflavone), apigenin (5,7,4′-trihydroxyflavone), diosmetin (5,7,3′-trihydroxy-4′-methoxyflavone) and luteolin (5,7,3′,4′-tetrahydroxyflavone).

The black locust is a plant from the subfamily of Faboideae in the family of legumes (Fabaceae) and is a relative of the pea and bean.

Confusion between species of both genera is almost impossible in higher latitudes, since acacias are native to subtropical and tropical areas and do not thrive in the cooler climates favoured by the black locust.

[16] Jesuit missionaries apparently[weasel words] fancied that this was the tree that supported St. John in the wilderness, despite its being native to North America.

[9] Robinia is a native North American genus, but traces of it are found in the Eocene and Miocene rocks of Europe.

[citation needed] Black locust's current range has been expanded by humans distributing the tree for landscaping and now includes Pakistan, India, Australia, Canada, China, Europe, Northern and South Africa, temperate regions in Asia, New Zealand, Southern South America.

[18] Black locust is a shade-intolerant species[17] and therefore is typical of young woodlands and disturbed areas where sunlight is plentiful and the soil is dry.

[9] When growing in sandy areas this plant can enrich the soil by means of its nitrogen-fixing nodules, allowing other species to move in.

[17] It specializes in colonizing disturbed areas and edges of woodlots before it is eventually replaced with taller or more shade-tolerant species.

Black locust is host to up to 67 species of lepidoptera,[19] and provides valuable cover when planted on previously open areas.

[12] Locust borer Megacyllene robiniae larvae carve tunnels into the trunk of the tree and make it more prone to being knocked down by the wind.

[12] Black locust is also attacked by Chlorogenus robiniae, a virus which causes witch's broom growths; clear leaflet veins are a symptom of the disease.

[21] The black locust is among the preferred reproductive hosts of the polyphagous shot-hole borer (PSHB, Euwallacea fornicatus).

[22] Black locust is considered invasive on its native continent, specifically in the western United States, New England region, northern California, and in the Midwest.

[27] Horses that consume the plant show signs of anorexia, depression, incontinence, colic, weakness, and cardiac arrhythmia.

Black locust has been spread and used as a plant for erosion control as it is fast growing and generally a tough tree.

Weather conditions can have quite an effect on the amount of nectar collected, as well; in Ohio for example, good locust honey flow happens in one of five years.

This means manual harvesting of flowers, eliminating the seeds and boiling the petals with sugar, in certain proportions, to obtain a light sweet and delicate perfume jam.

Although the bark and leaves are toxic, various reports suggest that the seeds and the young pods of the black locust are edible.

Obviating the mass application of fertilizers, black locust and other nitrogen-fixing tree and shrub species have gained importance in managed forestry.

[42] In fireplaces, it can be less satisfactory because knots and beetle damage make the wood prone to "spitting" coals for distances of up to several feet.

[citation needed] This native hardwood is also prized by North American shipwrights for making rot-resistant trunnels in traditional wooden ship construction.

It is very resistant to rot, and durable, making it prized for furniture, flooring, paneling, fence posts, and small watercraft.

Black Locust is a highly durable organic wood product that does not require chemical treatment to preserve its beauty for 50 years or longer.

[50] In 1900, the value of Robinia pseudoacacia was reported to be practically destroyed in nearly all parts of the U.S. beyond the mountain forests which are its home by locust borers which riddle the trunk and branches.

Young trees grow quickly and vigorously for a number of years, but soon become stunted and diseased, and rarely live long enough to attain any commercial value.