# Laburnum
**Laburnum**, commonly called golden chain or golden rain, is a small genus of deciduous trees and shrubs in the legume family (Fabaceae) native to central and southeastern Europe, grown for their hanging clusters of bright yellow pea-shaped flowers. The genus was first published by Fabricius in 1759, and Kew's Plants of the World Online gives its native range as central and southeastern Europe[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information). All parts of the plants, especially the pods and seeds, are poisonous because they contain quinolizidine alkaloids[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information).
| Key fact | Detail |
|---|---|
| Genus | *Laburnum* Fabr., Fabaceae, first published 1759; small trees or shrubs of forest edges and woodland scrub[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information) |
| Native range | Central and southeastern Europe, montane[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information) |
| Species | *L. alpinum* (Scotch laburnum) and *L. anagyroides* (common laburnum), plus the hybrid *L. × watereri*[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf) |
| Size | Common laburnum reaches 6.1–9.1 m at maturity; Scotch laburnum about 6.1 m[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf) |
| Flowers | Golden yellow flowers about 1.9 cm long on 15–25 cm pendulous racemes, blooming May to June[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf) |
| Toxicity | All parts contain the alkaloid cytisine, concentrated in seeds; ingestion at doses as low as 0.5 mg/kg body weight has been implicated in mass poisonings[3](https://www.bfr.bund.de/en/risk-communication/dialog-formats/bfr-poisonous-plants-garden/common-laburnum/) • [4](https://www.ncbi.nlm.nih.gov/sites/books/NBK587364/) |
| Long cultivation | Common laburnum first cultivated in 1560 and Scotch laburnum in 1596; both species reached Britain by the 16th century at the latest[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf) • [5](https://www.treesandshrubsonline.org/articles/laburnum/) |
## Description
Laburnums are small deciduous trees with leaves composed of three leaflets and bright yellow, pea-shaped flowers borne in pendent racemes[6](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details). The flowers are about 1.9 cm long and open from May to June; the fruit is a brown pod 5.1 to 7.6 cm long containing black seeds, which ripen from late August to October[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf). Common laburnum (*Laburnum anagyroides*, syn. *Cytisus laburnum*, *L. vulgare*) tends to be a low-branched, bushy, wide-spreading tree up to 8 m tall, while Scotch laburnum (*L. alpinum*) has a short, sturdy trunk and a flat to round-topped crown[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf) • [6](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details).
The two species are distinguished most easily by flowering time and hairiness: *L. alpinum* flowers about three weeks later than *L. anagyroides*, and its leaflets are almost the same color on both surfaces, whereas the leaflets of *L. anagyroides* are much paler beneath than above[7](https://citeseerx.ist.psu.edu/document?doi=35ade1944457255d97eb03202454efa658899cad&repid=rep1&type=pdf). *L. anagyroides* occupies warmer, drier sites and is more or less confined to alkaline soils[8](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-anagyroides/).
## Species and hybrid
The genus includes two wild species and a well-known hybrid. *Laburnum × watereri*, first published by Leopold Dippel in 1893, combines *L. alpinum* and *L. anagyroides*; crosses occur both in cultivation and in the wild, in the Italian South Tyrol and southern Switzerland where the parents grow together[9](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A501463-1/general-information) • [10](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-x-watereri/). The staggered flowering of the parents, with *L. alpinum* opening just as *L. anagyroides* finishes, probably limits hybridization in the wild[10](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-x-watereri/).
The hybrid is more vigorous and floriferous than either parent and is the preferred garden laburnum today, though all three forms are cultivated[11](https://fermanagh.bsbi.org/laburnum-anagyroides-medik). It sets very little seed, which reduces self-sowing and leaves more vigor for flowering[11](https://fermanagh.bsbi.org/laburnum-anagyroides-medik). The best-known clone, 'Vossii', was selected around 1875 by the Dutch nurseryman C. de Vos and bears racemes described as up to 60 cm long; it received the [Royal Horticultural Society](https://www.edgepedia.org/royal-horticultural-society)'s Award of Garden Merit in 1928 and has held it ever since[10](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-x-watereri/). A related graft chimera, *+[Laburnocytisus](https://www.edgepedia.org/laburnocytisus-adamii)* 'Adamii' (Adam's laburnum), comprises *Cytisus purpureus* grafted onto *L. anagyroides*[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information).
## Cultivation and history
Laburnums have been cultivated for centuries, primarily as ornamentals, and laburnum arches and walks are a feature of many large gardens[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf). The USDA Forest Service woody plant seed manual dates first cultivation of common laburnum to 1560 and Scotch laburnum to 1596[2](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf), and both species had reached Britain by the 16th century at the latest[5](https://www.treesandshrubsonline.org/articles/laburnum/). The herbalist Gerard recorded it growing in his London garden in 1597 under the names anagyris, laburnum, and beane trefoyle[12](https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Laburnum). European colonists introduced the tree into northeastern America[12](https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Laburnum).
In the garden, laburnums suit a sunny position with well-drained soil and are propagated by grafting; the Royal Horticultural Society rates common laburnum hardiness H6, hardy throughout the UK and northern Europe[6](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details). The plants may suffer from aphids, leaf-mining moths and flies, snails, powdery mildews, silver leaf, and honey fungus[6](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details).
## Wood and other uses
The wood is hard and was valued for small work: the [French name](https://www.edgepedia.org/french-name) *l'aubour* descends from laburnum, and the related form *arbois* (arc-bois) records that the ancient Gauls used the wood for bows, a use said to persist in parts of the Mâconnois where bows were found to keep their strength and elasticity for half a century[12](https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Laburnum). Kew's Legumes of the World entry also lists laburnum wood as a substitute for ebony[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information).
## Toxicity
All parts of the plant contain quinolizidine alkaloids, notably cytisine, concentrated primarily in the fruits and seeds[3](https://www.bfr.bund.de/en/risk-communication/dialog-formats/bfr-poisonous-plants-garden/common-laburnum/). Cytisine is a nicotine-like alkaloid with pharmacological effects similar to nicotine[13](https://www.sciencedirect.com/science/article/pii/S0379073809000371). A forensic case report describes a fatal cytisine intoxication in a 20-year-old man who drank tea prepared from *Laburnum anagyroides* plant material, with respiratory failure as the mechanism of death[13](https://www.sciencedirect.com/science/article/pii/S0379073809000371). Cytisine-containing plants including *Cytisus laburnum* have been implicated in mass poisonings of children and adults following ingestion at doses as low as 0.5 mg per kilogram of body weight[4](https://www.ncbi.nlm.nih.gov/sites/books/NBK587364/). Poisoning produces vomiting, drowsiness, weakness, sweating, pallor, and headaches[14](https://landscapeplants.oregonstate.edu/plants/laburnum-watereri), and the German Federal Institute for Risk Assessment advises contacting a poison center immediately after ingestion[3](https://www.bfr.bund.de/en/risk-communication/dialog-formats/bfr-poisonous-plants-garden/common-laburnum/). The RHS lists the plant as harmful if eaten, including for dogs, rabbits, and rodents[6](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details).
## References
1. [Laburnum Fabr., Plants of the World Online, Royal Botanic Gardens Kew](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A22728-1/general-information)
2. [Pijut, P. M., Laburnum Medik., in the USDA Forest Service Woody Plant Seed Manual](https://www.fs.usda.gov/nsl/Wpsm/Laburnum.pdf)
3. [Common Laburnum, Bundesinstitut für Risikobewertung (BfR)](https://www.bfr.bund.de/en/risk-communication/dialog-formats/bfr-poisonous-plants-garden/common-laburnum/)
4. [Plant Alkaloids Toxicity, StatPearls, NCBI Bookshelf](https://www.ncbi.nlm.nih.gov/sites/books/NBK587364/)
5. [Laburnum, Trees and Shrubs Online](https://www.treesandshrubsonline.org/articles/laburnum/)
6. [Cytisus laburnum, common laburnum, RHS Plant Profile](https://www.rhs.org.uk/plants/218286/cytisus-laburnum/details)
7. [Laburnum anagyroides and L. alpinum in Cardiganshire, Botanical Society of the British Isles](https://citeseerx.ist.psu.edu/document?doi=35ade1944457255d97eb03202454efa658899cad&repid=rep1&type=pdf)
8. [Laburnum anagyroides, Trees and Shrubs Online](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-anagyroides/)
9. [Laburnum × watereri (A.C.Rosenthal & Bermann) Dippel, Plants of the World Online, Kew](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A501463-1/general-information)
10. [Laburnum × watereri, Trees and Shrubs Online](https://www.treesandshrubsonline.org/articles/laburnum/laburnum-x-watereri/)
11. [Laburnum anagyroides, BSBI Fermanagh](https://fermanagh.bsbi.org/laburnum-anagyroides-medik)
12. [Laburnum, 1911 Encyclopædia Britannica, Wikisource](https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Laburnum)
13. [Fatal cytisine intoxication and analysis of biological samples with LC–MS/MS, Forensic Science International](https://www.sciencedirect.com/science/article/pii/S0379073809000371)
14. [Laburnum × watereri, Landscape Plants, Oregon State University](https://landscapeplants.oregonstate.edu/plants/laburnum-watereri)
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*Topic: Encyclopedia › Life and health › Plants and algae › Seed plants › Other flowering plants › Rosids › Fabaceae: legumes and the pea family › Titles A to L › Titles Di to L*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
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