laburnum

Laburnum is a small genus of flowering plants in the legume family (Fabaceae), native to the mountains of southern Europe and western Asia. The plants are deciduous shrubs or small trees grown primarily as ornamentals for their striking, pendulous racemes of yellow flowers that appear in late spring.

Leaves are pinnate with three leaflets, giving a light, delicate appearance. In spring the trees produce long clusters of pea-like flowers, typically 5–15 cm long, bright yellow and often fragrant.

Species and cultivation: The best-known species is Laburnum anagyroides, commonly called common laburnum; others include Laburnum alpinum and hybrids such as Laburnum x watereri. Laburnums are popular in temperate gardens and parks for their dramatic floral display. They prefer full sun, well-drained soil, and are hardy to roughly USDA zones 5–7, though climate influences tolerance. They can reach several meters in height and are often grown as small trees or large shrubs.

Toxicity: Laburnum is highly poisonous if ingested. All parts contain cytisine, a potent alkaloid; seeds and pods pose the greatest risk and can cause vomiting, seizures, coma, and potentially death in humans and livestock. Plants are usually kept away from children and animals, and care is advised when handling.

Ecology and uses: As a legume, laburnum forms nitrogen-fixing nodules and can enrich soils. In addition to ornamental use, the wood—pale yellow-brown—is valued for carving and turnery in some regions, though handling remains limited by toxicity.