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Robinia pseudoacacia
Toxic🐾Gewöhnliche Robinie · (Robinia pseudoacacia)
Legume family (Fabaceae)
Description
Native to North America, this fast-growing tree of the pea family (Fabaceae) has become naturalised across much of Europe and is easy to spot in early summer by its fragrant white flower clusters, which draw large numbers of bees and yield a prized blossom honey. Only the fully opened flowers are traditionally used, and always deep-fried or otherwise cooked — raw or in larger amounts they can cause mild stomach irritation. IMPORTANT: the bark, roots, young shoots, leaves and especially the pea-like seeds contain the toxic lectin robin along with robinin and are poisonous to both people and animals. Wood shavings and fallen leaves must therefore never be used as bedding or feed in animal husbandry. Children should be taught early about the toxicity of the tempting-looking pods.
🌿 Risk of confusion — read before wild-harvesting!
Bark, roots, young shoots, leaves and seeds are toxic (lectin robin/phasin, flavonol glycoside robinin, wystin). Only fully opened flowers are considered edible in folk cuisine - and only deep-fried or otherwise heated, not raw. Do not confuse seedlings/suckers with edible wild greens. Do not use wood shavings, sawdust, wood chips or fallen leaves of Robinia in horse, cattle or rabbit stables - even small amounts of bark can be lethal. Educate children about toxicity - the sweet pea-like pods are particularly tempting. ASPCA classification (accessed 2026-08-10): toxic to dogs and cats. The ASPCA classifies the whole genus this way.
CONTRAINDICATED during pregnancy
No therapeutic use of bark or seed preparations in pregnancy (toxic lectins). Deep-fried flower fritters in household amounts are considered safe, but moderation is advised.
Robinia is the most important nectar source for so-called 'acacia honey' - botanically actually black-locust honey, since true acacia (Acacia) is a different genus. The honey is pale, mild, liquid (crystallises very slowly due to high fructose content) and is regarded as a premium beekeeping product. Yields of 500-1000 kg honey per hectare of Robinia stand are possible in good weather.
Preparation & dosage
Used in park and street-tree planting since the 17th century (introduced to Europe in 1601 by Jean Robin, court gardener to Henry IV) as a robust, fast-growing shade tree tolerant of drought and urban climate. Cultivars such as 'Umbraculifera' (mop-head locust) and 'Frisia' (yellow-leaved) are established street trees. Caution: root suckers and invasive behaviour in semi-natural areas.
Black-locust timber is exceptionally hard, heavy and durable (durability class 1-2 per EN 350, comparable to teak or oak). Classical uses: vineyard stakes, fence posts, railway sleepers (historically), boat building, tool handles, playground equipment and outdoor furniture. Considered a sustainable European hardwood alternative to tropical timbers (FSC-certified plantations in Hungary, Romania).
As a legume, Robinia lives in symbiosis with Rhizobium bacteria in root nodules and fixes atmospheric nitrogen (up to 100-300 kg N/ha/year). Historically used to reforest erosion-prone soils, mine spoils and nutrient-poor sites. Now critically assessed in nature conservation: nitrogen input displaces species-rich nutrient-poor dry grasslands and oligotrophic habitats.
Historical documentation only — do NOT use
These internal applications are historically documented. This plant is highly toxic — self-treatment can cause severe poisoning or death. For documentation only, explicitly NOT a recommendation.
The intensely fragrant white flower clusters are harvested in May/June and traditionally deep-fried in beer or pancake batter as 'Akazienkuechle' or Italian 'fritti di acacia'. Also used for syrup or for flavouring sugar and liqueurs. Only fully opened flowers are used - stems, leaves, bark and seeds are toxic (robin/robinin).
Preparation & dosage
Important folk-medicinal and veterinary note: bark, roots, young shoots and seeds contain robin (toxic lectin/phasin, heat-labile), robinin (flavonol glycoside) and wystin. Ingestion by humans or animals (especially horses, cattle, pigs, rabbits, birds) leads to vomiting, bloody diarrhoea, mydriasis, weakness, circulatory collapse and seizures. Horse poisonings from bark gnawing or Robinia shavings in bedding are regularly documented.
Bark, roots, young shoots, leaves and seeds are toxic (lectin robin/phasin, flavonol glycoside robinin, wystin). Only fully opened flowers are considered edible in folk cuisine - and only deep-fried or otherwise heated, not raw. Do not confuse seedlings/suckers with edible wild greens. Do not use wood shavings, sawdust, wood chips or fallen leaves of Robinia in horse, cattle or rabbit stables - even small amounts of bark can be lethal. Educate children about toxicity - the sweet pea-like pods are particularly tempting. ASPCA classification (accessed 2026-08-10): toxic to dogs and cats. The ASPCA classifies the whole genus this way.
No therapeutic use of bark or seed preparations in pregnancy (toxic lectins). Deep-fried flower fritters in household amounts are considered safe, but moderation is advised.
Flower preparations in culinary amounts are safe. No bark/seed preparations. Data on lactation insufficient.
Educate children thoroughly about toxicity of bark, flower shoots and seed pods. The pods resemble peas or beans and are frequently put in the mouth during play - documented poisoning cases in paediatric literature. Deep-fried flowers in small amounts are safe.
Drug interactions
Antikoagulanzien
Theoretical risk with consumption of larger amounts of flower preparations: Robinia constituents (flavonoids, robinin) may affect platelet function. Not systematically studied clinically.
Contraindications
- Internal use of bark, seeds, roots or leaves in any form (tea, tincture, powder) - toxic lectins.
- Use as fodder for horses, cattle, sheep, goats, rabbits or birds; Robinia wood shavings/sawdust as bedding in animal husbandry.
- Raw consumption of flowers in larger amounts (mild gastric irritation from heat-labile constituents).
Harvested part: bark, seeds, leaves
- Time of day:
- Late morning in dry, sunny weather once the dew has evaporated - flower aroma is then most intense. Only fully opened white flower clusters (remove stems and leaves).
- Drying:
- Fresh processing recommended (deep-fry on the day of harvest). For drying, spread loosely on cloths in a shaded, airy place, max 35 degrees C. Dried flowers lose aroma rapidly.
- Storage:
- 6 months — Store dried flowers in dark, tightly sealed glass or tin containers, cool and dry. Flower syrup keeps refrigerated for 6-12 months.
- Time of day:
- Timber harvest (felling) during winter dormancy - water content of the wood is then lowest and durability highest. Minimum age for valuable timber: 40-60 years.
- Drying:
- Air-dry stem timber outdoors for 1-2 years, then condition to final moisture (12-15 percent for furniture, 18-20 percent for outdoor use). Black-locust timber is heavy (density approx. 720-790 kg/m3) and tends to crack during drying - slow drying required.
- Storage:
- Dry, covered, well ventilated. When stored near animal facilities, strict separation from horse, cattle and rabbit areas (toxicity).
- Robin (Phasin, toxisches Lektin)OtherBark
Heat-labile toxic lectin (phytohaemagglutinin type) in bark, roots and seeds. Mainly responsible for acute toxicity: agglutinates red blood cells, damages gut mucosa, leads to vomiting, bloody diarrhoea and circulatory collapse. Largely destroyed by prolonged cooking.
- RobininGlycosideFlower
Flavonol glycoside (kaempferol-3-O-robinoside-7-O-rhamnoside), name-giving for Robinia. Found in flowers, leaves and bark. Mildly diuretic and toxic in high doses.
- Wystin (Wistarin)GlycosideBark
Another toxic glycoside in bark and roots, chemically related to robinin. Contributes to overall toxicity.
- Ätherisches Öl (Linalool, cis-Ocimen, Methylanthranilat)Essential oilContent: SpurenanteileFlower
Small amounts of essential oil with linalool, cis-ocimene and methyl anthranilate are responsible for the intense, sweet, orange-blossom-like fragrance of the white flower clusters. Strongly attracts honeybees and bumblebees.
- Flavonoide (Acaciin, Robinetin, Apigenin, Luteolin)FlavonoidFlower
Flavones and flavonol glycosides in flowers and leaves with antioxidant properties. Acaciin (acacetin rutinoside) is name-giving for the colloquial reference to 'acacia'.
- Gerbstoffe (Robitannine)TanninBark
Condensed tannins (robitannins, catechin tannins) in the bark contribute to the high durability of the timber (natural wood preservation against fungi and rot).
- Asparagin und freie AminosäurenOtherSeed
Considerable amounts of asparagine and other free amino acids in seeds and young tissues - a consequence of nitrogen fixation by Rhizobium symbiosis in the root nodules.
- Fructose (Honig-Bestandteil)OtherFlower
Robinia flower nectar contains a comparatively high fructose share. This results in the characteristically liquid, slowly crystallising 'acacia honey' with a high fructose/glucose ratio (about 1.4-1.7).
- [3]MonographPlants For A Future - Robinia pseudoacacia(accessed: 2026-05-27)
- [4]MonographCABI Invasive Species Compendium - Robinia pseudoacacia (black locust)(accessed: 2026-05-27)
- [5]MonographBotanikus - Giftpflanze Robinie (Robinia pseudoacacia)(accessed: 2026-05-27)
- [6]MonographEFSA Compendium of Botanicals - Robinia pseudoacacia L.(accessed: 2026-05-27)
- [7]MonographASPCA Animal Poison Control — Locust (Robinia spp.)(accessed: 2026-08-10)
- [8]MonographCliniTox Giftpflanzen — Robinia pseudoacacia L.: stark giftig ++ (Institut für Veterinärpharmakologie und -toxikologie, Universität Zürich)(accessed: 2026-08-10)
- [1]WikipediaGewöhnliche Robinie (Wikipedia DE)(accessed: 2026-05-27)
- [2]WikipediaRobinia pseudoacacia (Wikipedia EN)(accessed: 2026-05-27)