View source for Laburnum

{{for|the suburb of Melbourne|Laburnum, Victoria}}
:''"Indian laburnum" is the [[Golden Shower Tree]], a distant relative of the genus ''Laburnum.
{{Taxobox
| name = ''Laburnum''
| image = Laburnum_anagyroides2.jpg
| image_width = 240px
| image_caption = Common Laburnum – flowers
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Dicotyledon|Magnoliopsida]]
| ordo = [[Fabales]]
| familia = [[Fabaceae]]
| subfamilia = [[Faboideae]]
| tribus = [[Genisteae]]
| genus = '''''Laburnum'''''
| genus_authority = [[Philipp Conrad Fabricius|Fabr.]]
| subdivision_ranks = Species
| subdivision = 
''[[Laburnum anagyroides]]''<br/>
''[[Laburnum alpinum]]''
}}

'''''Laburnum''''' (commonly called '''Golden Chain''') is a genus of two species of small [[tree]]s in the subfamily [[Faboideae]] of the pea family [[Fabaceae]], ''[[Laburnum anagyroides]]'' ('''common laburnum''') and ''[[Laburnum alpinum|L. alpinum]]'' ('''Alpine laburnum'''). They are native to the mountains of southern [[Europe]] from [[France]] to the [[Balkan Peninsula]]. Some botanists include a third species, ''Laburnum caramanicum'', but this native of southeast Europe and [[Asia Minor]] is usually treated in a distinct genus ''[[Podocytisus]]'', more closely allied to the [[broom (shrub)|brooms]].

[[Image:Laburnum anagyroides flowering.jpg|thumb|left|Laburnum tree in full flower.]]
They have yellow pea-[[flower]]s in pendulous [[raceme]]s 10–30&nbsp;cm (4–12&nbsp;in) long in spring, which makes them very popular garden trees. In ''L. anagyroides'' the racemes are 10–20&nbsp;cm (4–8&nbsp;in) long, with densely packed flowers; in ''L. alpinum'' the racemes are 20–30&nbsp;cm (8–12&nbsp;in) long, but with the flowers sparsely along the raceme.

The leaves are trifoliate, somewhat like a [[clover]], the leaflets typically 2–3 cm (¾–1¼&nbsp;in) long in ''L. anagyroides'' and 4–5&nbsp;cm (1½–2&nbsp;in) long in ''L. alpinum''.

Most garden specimens are of the hybrid between the two species, ''[[Laburnum × watereri]]'' ('''Voss's Laburnum'''), which combines the longer racemes of ''L. alpinum'' with the denser flowers of ''L. anagyroides''; it also has the benefit of low seed production (Laburnum seed can poison anyone who mistakes the seeds for [[pea]]s).

The yellow flowers are responsible for the old poetic name 'golden chain tree' (also spelled golden chaintree or goldenchain tree).

All parts of the plant are [[poison]]ous and can be lethal if consumed in excess. Symptoms of laburnum poisoning may include intense sleepiness, vomiting, convulsive movements, coma, slight frothing at the mouth and unequally dilated pupils. In some cases, diarrhea is very severe and at times the convulsions are markedly [[tetanic]]. The main toxin in the plant is [[Cytisine]], a nicotinic receptor agonist.
It is used as a food plant by the [[larva]]e of some [[Lepidoptera]] species including [[Buff-tip]].

The heart-wood of a laburnum may be used as a substitute for ebony or rosewood, very hard and a dark chocolate brown, with a butter-yellow sapwood.

==Cultural references==
In the TV mystery series ''[[Mother Love (TV series)|Mother Love]]'', Helena ([[Diana Rigg]]) muses over what plant she should use to poison a pair of children and chooses the laburnum, saying, "Laburnum!  Such a pretty tree – and so many ''of'' them!"

[[Sylvia Plath]] referred to the image of the laburnum tree and "its blond colonnades" in her poem "The Arrival of the Bee Box", first published posthumously in the collection [[Ariel (Plath)|''Ariel'']] (1965).

Oscar Wilde referred to laburnum in his novel, ''[[The Picture of Dorian Gray]]'', noting the "...honey-sweet and honey-colored blossoms of a laburnum...".

In [[Henrico County, Virginia]], just outside of the [[Richmond, Virginia|Richmond]] city limits, Laburnum Avenue is one of the main thoroughfares.  The street is lined with many laburnum trees.

In [[W. W. Jacobs]]' short story "[[The Monkey's Paw]]", the name of the house of the family is "Laburnum Villa", suggesting that the house is not as safe and protective as initially described.

In the Doctor Who serial "[[The Mark of the Rani]]", the [[Sixth Doctor]] suggests that if the [[Master]] turned into a tree, it would be a laburnum, because they have poisonous pods. 

The novel ''[[A Melon for Ecstasy]]'' by [[John Fortune]] and [[John Wells (satirist)|John Wells]] is, in part, about the main character's forbidden love affair with the laburnum in his back yard.

Laburnum seeds are the agent of suspected poisoning in the [[Daphne du Maurier]] novel ''[[My Cousin Rachel]]''.

In Redwall novel ''[[Triss]]'', the secret entrance to Brockhall is between an ash tree and a laburnum tree.

In [[Ted Hughes]] poem "The Laburnum Top," the central character goldfinch sits and feeds its young ones on this tree.

==References and external links==
*[http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Laburnum&SPECIES_XREF=&TAXON_NAME_XREF=&RANK= Flora Europaea: ''Laburnum'']
*[http://www.ildis.org/ ILDIS Legume Database]
*[http://www.haworth-village.org.uk/nature/time-lapse/time-lapse.asp?pic=16 time lapse video] of a year in the life of a laburnum tree.
*[http://www.botanical.com/botanical/mgmh/l/labrun02.html Grieve, 'A Modern Herbal' (1931)]


{{Commons|Laburnum x watereri}}
{{Commons|Laburnum}}
{{tree-stub}}

[[Category:Faboideae]]
[[Category:Poisonous plants]]

[[ca:Laburnum]]
[[da:Guldregn]]
[[de:Goldregen (Pflanze)]]
[[es:Laburnum]]
[[eo:Orpluvo]]
[[fr:Laburnum]]
[[hsb:Kitkowc]]
[[is:Gullregn]]
[[lt:Pupmedis]]
[[hu:Aranyeső]]
[[nl:Goudenregen]]
[[no:Gullregn (Laburnum)]]
[[pl:Złotokap]]
[[pt:Laburnum]]
[[fi:Kultasadepensaat]]
[[sv:Gullregnssläktet]]
[[tl:Laburnum]]
[[Category:2Fix]]