Laburnum n : flowering shrubs or trees having bright yellow flowers; all parts of the plant are poisonous [syn: genus Laburnum]
- For the suburb of Melbourne, see Laburnum,
- "Indian laburnum" is the Golden Shower Tree, a distant relative of the genus Laburnum.
They have yellow pea-flowers in pendulous racemes 10-30 cm (4-12 in) long in spring, which makes them very popular garden trees. In L. anagyroides the racemes are 10-20 cm (4-8 in) long, with densely packed flowers; in L. alpinum the racemes are 20-30 cm (8-12 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 in) long in L. anagyroides and 4-5 cm (1½-2 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 toxicity is a common cause of poisoning in young children, who mistake the seeds for peas).
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 poisonous 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.
Despite the plant's toxicity, it is used as a food plant by the larvae of some Lepidoptera species including Buff-tip.
Cultural referencesSylvia 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 (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...".
References and external links
Laburnum in Danish: Guldregn
Laburnum in German: Goldregen (Pflanze)
Laburnum in Spanish: Laburnum
Laburnum in Esperanto: Orpluvo
Laburnum in French: Laburnum
Laburnum in Icelandic: Gullregn
Laburnum in Lithuanian: Pupmedis
Laburnum in Norwegian: Gullregn
Laburnum in Polish: Złotokap
Laburnum in Portuguese: Laburnum
Laburnum in Finnish: Kultasadepensaat
Laburnum in Swedish: Gullregn