Plant of the Month - June 2012

Laburnum anagyroides 

Mark yonder, 

how the long laburnum drips 

Its jocund spilth of fire, its honey of wild flame!

 —Francis Thompson, Sister Songs (1895) 

 Laburnum Anagyroides - Public Domain

Laburnum anagyroides (Common Laburnum, Golden Chain or Golden Rain) is a species of small deciduous trees or large shrubs up to 7 m tall in the genus Laburnum, native to Central and Southern Europe. It is a popular ornamental plant, along with the other species in the genus, L. alpinum, and especially the hybrid between them, L. × watereri. L. anagyroides blooms in late spring with pea-like, yellow flowers densely packed in pendulous racemes 10-20 cm (4-8 in) long. 

The yellow flowers are responsible for the old poetic name 'golden chain tree' (also spelled golden chaintree or goldenchain tree). The plants can be found in the Upper Wilderness of the gardens, and as usual are stunning examples. 

 

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. The Laburnum plant will poison anyone who consumes the seeds for mistaking them for peas. Consequently this beautiful brightly coloured plant has a somewhat dark reputation. 

All parts of the plant contain Cytisine. Cytisine was discovered in 1863 by Husemann and Marme. It is a white, crystalline solid, of a bitter, somewhat caustic taste, with a very poisonous action. All parts of the laburnum 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. 

As with most other plants of this type though if sensible precautions are observed (don’t eat it, keep children away from it, wash hands after handling etc.) risks are minimised. Cytisine is also an ingredient in some insecticides. Detail of the flowers A shrub with smooth bark, dark green spreading branches and pendulous and pubescent twigs. The leaves (made of three leaflets) have a long pedunculus, are smooth on the upperside and hairy on the underside. The flowers are golden yellow and sweet scented, are grouped in pendulous racemes up to 25 cm long, and typically bloom in May. 

The seeds are legumes with large numbers of black seeds that contain cytisine, which is an alkaloid poisonous not only to humans but also to goats and horses, especially when not ripe. However, some wild animals such as hares and deer can feed on them without any ill-effects, and because of this the plant is believed to have magic properties in some regions. 

Growth 

Laburnum trees are not too fussy as to which type of soil they live in, as they can thrive in well drained light soil, heavy clay soil, acidic soil or a chalky alkaline soil. Make sure that your plant is situated in full sun, as laburnums are sun worshippers. The best time to plant laburnum seeds is from September to November. The best time to take a laburnum cutting is from December to February. As long as you plant your laburnum tree in full sun, then there shouldn't really be much to do thereafter. 

Laburnums are notorious for being short-lived, but they offer copious amounts of seeds every year, so they tend to regenerate themselves. Many gardeners try to remove the drying seed pods from laburnum trees as this encourages a good show of flowers the following year. Uses Despite its poisonous nature, Laburnum wood does have some use. The heart-wood of the Laburnum was often used as an Ebony substitute as it is very hard and coloured a dark chocolate brown. The sapwood surrounding the heart-wood is in contrast a bright yellow. The wood has been used for making the handles of tools and for use in various crafts. It is also ideal for making posts, for woodturning and as fuel. 

In the past (and today on historic re-enactments) it was used for making bows. Laburnum has historically been used for cabinetmaking and inlay, as well as for musical instruments. In addition to such wind instruments as recorders and flutes, it was a popular wood for Great Highland bagpipes before taste turned to imported dense tropical hardwoods such as cocuswood, ebony, and African blackwood.

Folklore

I’m afraid quaint folklore tales regarding the Laburnum are rather thin on the ground, generally focusing on the ‘unlucky’ side of things (which considering the toxic properties of the plant is hardly surprising) and making very boring reading, truth be told. 

Laburnums have a much more colourful CV in fiction however; In the TV mystery 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!" 

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 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 Wizardborn, the third book in Dave Wolverton's (David Farland) The Runelords series, Averan, the Earth Warden, chooses her staff of power from the wood of the laburnum tree. It has also been stated that The writer J. R. R. Tolkien was inspired by the laburnum for his creation of Laurelin, one of the two mythological trees in The Silmarillion, and Tolkien's description of it is strongly influenced by Thompson's verses. 

So that’s the laburnum. Enjoy, but handle with care! Check out this beautiful plant at your next visit. 

Thank you: 

Gordon Sammons

http://www.thepoisongarden.co.uk/atoz/laburnum_anagyroides.htm

http://en.wikipedia.org/wiki/Laburnum

http://en.wikipedia.org/wiki/Laburnum_anagyroides

http://www.botanical.com/botanical/mgmh/l/labrun02.html

http://commons.wikimedia.org/wiki/Laburnum_anagyroides

The photographs taken by Graham High in this work are licensed under a Creative Commons Attribution-NonCommercial 2.0 UK: England & Wales License.