''Laburnum alpinum'', the Scotch laburnum, Scottish laburnum or alpine laburnum, is a

leguminous A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock for ...

, (''Leguminosae''), deciduous tree.

Description

''Laburnum alpinum'' is similar to '' Laburnum anagyroides'', it grows to by , at a fast rate. It is hardy to zone 5. It is in flower from May to June, and the seeds ripen from September to October. The panicles of vanilla scented, pea-like flowers are hermaphrodite (having both male and female organs) and are pollinated by insects. The fruit is a pod or legume, the seeds green at first but becoming shiny black. The leaves are ''cholagogue'' and purgative. All parts of this plant are poisonous if consumed in large enough quantities and should not be eaten or used internally.

Distribution

It is native to Central and Southern Europe and has naturalized in Scotland. ''L. alpinium'' and ''L. anagyroides'' Medic. both are common as a garden escape in

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...

.Hackney, P. (Ed) ''Stewart and Corry's Flora of the North-east of Ireland''. Institute of Irish Studies , The Queen's University of Belfast. (HB)

Cultivation

''Laburnum alpinum'' is cultivated as an ornamental tree. Plants can be successfully transplanted even when quite large. The most common ornamental Laburnum plant is a hybrid of this species and '' Laburnum anagyroides'', '' Laburnum × watereri''. The plant prefers well-drained, light (sandy), medium (loamy) soil but tolerates heavy clay and nutritionally poor soils. Preferring acid, neutral and basic (alkaline) soils, it can grow in semi-shade (light woodland) or full sun. It can withstand strong winds but not maritime exposure and tolerates atmospheric pollution. The plant is notably susceptible to honey fungus. ''Laburnum'' has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.

References

{{Taxonbar, from=Q3497019 Genisteae Trees of Europe Flora of Europe Flora of Italy Garden plants of Europe Ornamental trees