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Robinia pseudoacacia - L.

Common Name Black Locust, Yellow Locust
Family Fabaceae or Leguminosae
USDA hardiness 4-9
Known Hazards All parts of the plant (except the flowers) and especially the bark, should be considered to be toxic[4, 65, 76]. The toxins are destroyed by heat[65].
Habitats Woods and thickets[43], especially in deep well-drained calcareous soils[149].
Range Eastern N. America - Appalachian and Ozark mountain ranges. Naturalized in Britain[17].
Edibility Rating    (3 of 5)
Other Uses    (0 of 5)
Weed Potential Yes
Medicinal Rating    (2 of 5)
Fully Hardy Well drained soil Moist Soil Full sun
Robinia pseudoacacia Black Locust, Yellow Locust

Robinia pseudoacacia Black Locust, Yellow Locust


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Bloom Color: White. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Oval, Upright or erect.

Physical Characteristics

 icon of manicon of lolypop
Robinia pseudoacacia is a deciduous Tree growing to 25 m (82ft) by 15 m (49ft) at a fast rate.
It is hardy to zone (UK) 3. It is in flower in June, and the seeds ripen from November to March. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees.
It can fix Nitrogen.
It is noted for attracting wildlife.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought. It can tolerate atmospheric pollution.



Woodland Garden Canopy;

Edible Uses

Edible Parts: Flowers;  Oil;  Seed;  Seedpod.
Edible Uses: Condiment;  Drink;  Oil.

Seed - cooked[2, 55, 61]. Oily[161]. They are boiled and used like peas[183]. After boiling the seeds lose their acid taste[213]. The seed is about 4mm long and is produced in pods up to 10cm long that contain 4 - 8 seeds[82]. A nutritional analysis is available[218]. Young seedpods - cooked[105]. The pods contain a sweetish pulp that is safe to eat and is relished by small children[201]. (This report is quite probably mistaken, having been confused with the honey locust, Gleditsia spp[K].) A strong, narcotic and intoxicating drink is made from the skin of the fruit[13]. Piperonal is extracted from the plant, it is used as a vanilla substitute[105]. No further details. All the above entries should be treated with some caution, see the notes at the top of the page regarding toxicity. Flowers - cooked. A fragrant aroma, they are used in making jams and pancakes[7, 183]. They can also be made into a pleasant drink[183].

Figures in grams (g) or miligrams (mg) per 100g of food.
Seed (Dry weight)
  • 0 Calories per 100g
  • Water : 0%
  • Protein: 21g; Fat: 3g; Carbohydrate: 0g; Fibre: 28g; Ash: 6.8g;
  • Minerals - Calcium: 1400mg; Phosphorus: 0.3mg; Iron: 0mg; Magnesium: 0mg; Sodium: 0mg; Potassium: 0mg; Zinc: 0mg;
  • Vitamins - A: 0mg; Thiamine (B1): 0mg; Riboflavin (B2): 0mg; Niacin: 0mg; B6: 0mg; C: 0mg;
  • Reference: [ 218, 269]
  • Notes:

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Antispasmodic;  Antiviral;  Aromatic;  Cancer;  Cholagogue;  Diuretic;  Emetic;  Emollient;  
Febrifuge;  Laxative;  Narcotic;  Purgative;  Tonic.

Febrifuge[13, 46]. The flowers are antispasmodic, aromatic, diuretic, emollient and laxative[218]. They are cooked and eaten for the treatment of eye ailments[218]. The flower is said to contain the antitumor compound benzoaldehyde[269]. The inner bark and the root bark are emetic, purgative and tonic[4, 7, 218, 257]. The root bark has been chewed to induce vomiting, or held in the mouth to allay toothache[222, 257], though it is rarely if ever prescribed as a therapeutic agent in Britain[4]. The fruit is narcotic[13]. This probably refers to the seedpod. The leaves are cholagogue and emetic[7]. The leaf juice inhibits viruses[218].

Other Uses

Dye;  Essential;  Fibre;  Fuel;  Oil;  Soil stabilization;  Wood.

A drying oil is obtained from the seed[2, 7]. An essential oil is obtained from the flowers. Highly valued, it is used in perfumery[7, 57, 100]. A yellow dye is obtained from the bark[223]. Robinetin is a strong dyestuff yielding with different mordants different shades similar to those obtained with fisetin, quercetin, and myricetin; with aluminum mordant, it dyes cotton to a brown-orange shade[269]. The bark contains tannin, but not in sufficient quantity for utilization[223]. On a 10% moisture basis, the bark contains 7.2% tannin and the heartwood of young trees 5.7%[223]. The bark is used to make paper and is a substitute for silk and wool[13]. Trees sucker freely, especially if coppiced, and they can be used for stabilizing banks etc[200, 226]. Wood - close-grained, exceedingly hard, heavy, very strong, resists shock and is very durable in contact with the soil. It weighs 45lb per cubic foot and is used in shipbuilding and for making fence posts, treenails, floors etc[4, 7, 11, 13, 46, 61, 82, 149, 171, 227]. A very good fuel[82], but it should be used with caution because it flares up and projects sparks[226]. The wood of Robinia pseudoacacia var. rectissima, the so called 'Long Island' or 'Shipmast' locust, has a greater resistance to decay and wood borers, outlasting other locust posts and stakes by 50 - 100%[269].

Cultivation details

Agroforestry Services: Nitrogen;  Agroforestry Services: Windbreak;  Fodder: Bank;  Industrial Crop: Biomass;  Management: Coppice;  Management: Standard;  Minor Global Crop;  Other Systems: SRC.

Landscape Uses:Erosion control, Firewood, Aggressive surface roots possible. Succeeds in any well-drained soil, preferring one that is not too rich[1, 200]. Succeeds in dry barren sites, tolerating drought and atmospheric pollution[60, 200]. Succeeds in a hot dry position. The plant is reported to tolerate an annual precipitation in the range of 61 to 191cm, an annual temperature in the range of 7.6 to 20.3°C and a pH of 6.0 to 7.0[269]. A fast-growing tree for the first 30 years of its life[188, 269], it can begin to flower when only 6 years old, though 10 - 12 years is more normal[229]. The flowers are a rich source of nectar and are very fragrant[82] with a vanilla-like scent[245]. The branches are brittle and very liable to wind damage[200]. When plants are grown in rich soils they produce coarse and rank growth which is even more liable to wind damage[11, 200]. The plants sucker freely and often form dense thickets, the suckers have vicious thorns[226]. There are some named varieties selected for their ornamental value[188], some of these are thornless[226]. Any pruning should be done in late summer in order to reduce the risk of bleeding[200]. The leaves are rich in tannin and other substances which inhibit the growth of other plants[13]. A very greedy tree, tending to impoverish the soil[13]. (Although a legume, I believe it does not fix atmospheric nitrogen[K]) A very good bee plant[7, 13, 20, 201]. This species is notably resistant to honey fungus[88, 200]. Special Features: North American native, Invasive, Naturalizing, All or parts of this plant are poisonous, Attracts butterflies, Fragrant flowers, Blooms are very showy.


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Seed - pre-soak for 48 hours in warm water and sow the seed in late winter in a cold frame[80]. A short stratification improves germination rates and time[80]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in the following summer. Other reports say that the seed can be sown in an outdoor seedbed in spring[78, 98]. The seed stores for over 10 years[113]. Suckers taken during the dormant season.

Other Names

If available other names are mentioned here

Found In

Countries where the plant has been found are listed here if the information is available

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status

IUCN Red List of Threatened Plants Status :

Related Plants
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Robinia luxuriansNew Mexico locust10
Robinia neomexicanaNew Mexico Locust, Rusby's locust, Locust11
Robinia viscosaClammy Locust, Hartweg's locust00


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Botanical References


Links / References

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Readers comment

Klaus Dichtel   Tue Dec 25 17:22:37 2001

I wonder how Ken comes to believe it doesn`t fix atmospheric nitrogen. All other sources are telling the opposite, e.g. Martin Crawford/"Nitrogen-fixing Plants"

Klaus Dichtel   Sat Jan 5 21:26:03 2002

In the german PC-mailinglist, Jürgen Wahl (j.orca@t-online.de) says that he saw nodulatet roots and N-loving plants nearby such as utrica ssp., galium aparine and sambucus nigra. Here his original message:"...Bis jetzt hatte jede Robinie der ich an die Wurzeln gegangen bin Knöllchen +die sind bei allenLeguminosen ort derSymbiose die N aus der Luft bindet. Fernerhabe ich bis heute in jedem Robiniengehölz eine N-liebende Begleitflora gefunden(Brennnessel,Klettenlabkraut,Hollunderetc.)..."

Miroslav Schlossberg   Tue May 24 17:42:19 2005

I could not find any health related info about Robinia pseudoacacia flovers (Flores). Where I live, it is named Akacija (read: Acacia, the same, only without "j"). All I could find is similar plant familly: Leguminosae/Mimosaceae Lat: Acacia senegal. Here, in Craotia, where I live, people is making tea of flowers. Do you have any data about its influences on human body?


Greetings from Croatia!

Thank you!

rabbe   Mon Jan 2 2006

Altough most parts of Robinia pseudoacacia are toxic for humans. It can be used as a tree fodder. See for example an article about silvopasture in Greece: Forage production of woody fodder species and herbaceous vegetation in a silvopastoral system in northern Greece, by Ainalis and Tsiouvaras

rabbe   Mon Jan 2 2006

An addition to my previous comment. Robinia pseudoacacia is toxic for horses and highly toxic for chicken! The following study is available on internet: Evaluation of Robinia pseudoacacia L. as Browse for Meat Goat Production in the Southeastern USA http://www.lib.ncsu.edu/theses/available/etd-11242003-154755/unrestricted/etd.pdf

john walker   Sat Jul 11 2009

why might Frisia type of Robinia Pseudo be dieing in large numbers. This is occurring after the leaves fall off early and don't renew the following year?

   Dec 28 2010 12:00AM

Greatings, in my opinion these is one of the most adaptable plants i know. I've found it from southern Portugal to eastern Poland, from the stepic areas of central spain to the rainy slopes of french Pireneys and suiss pre-alps. Is quite abundant in southern France beeing a common sight everywere. As a pyoneer speeces it can prepare soils and ecossistems for more demanding tree speeces forming woods that atract wildlife as a refuge and feeding area. J.Ferro

http://plants.usda.gov/java/charProfile?symbol=ROPS&format=print — gives details on Robinia pseudoacacia.   Feb 10 2016 12:00AM

According to the USDA plant database, this tree fixes nitrogen at a medium rate, which translates to 85-160 lb. N/acre/year. See http://plants.usda.gov/java/charProfile?symbol=ROPS&format=print.
USDA plant database

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