Laburnums

I have always fancied growing a laburnum tree but have restrained myself, not because it is poisonous in all its parts, but in my small garden I just can't spare the space.


A fine tree stands in Bodleian Close and as I paused to take a photograph earlier today I could hear the humming of bees.

A fine specimen of Laburnum anagroides in Bodleian Close.

8 May, 2020

If ever the tree is cut down the valuable timber would readily be employed by someone doing fine wood turning or marquetry.


The genus contains only two species and both are native to Europe. The so-called Scotch Laburnum (Laburnum alpinum) grows wild in south central Europe but rarely self-sows. The other European species, and the one photographed above, is L. anagroides; it occurs wild in roughly the same region. It is far more commonly seen in gardens and frequently self-sows on to waste ground, railway banks and so on. For some puzzling reason it seems to have been widely planted in the west of Wales

The flowers show clearly that laburnum is a member of the

pea family, Fabaceae.

There can be little argument regarding the tree's beauty and this led to laburnums being extensively planted in, for example, school grounds. The poisonous properties of the plant are down to the presence of an alkaloid, cytisine, and it is particularly concentrated in the seed pods. It is hard to imagine kids going round munching these but they do look like tiny peas and during the 1970's there were estimated to be 3000 hospital admissions a year due to their ingestion. Fortunately in most cases the children's stomachs were pumped before too much harm was done. But this led to a mini-panic and many trees were removed.

Should we have been so worried? Lupins also contain various alkaloids and again it is the pods and seeds that contain the highest concentrations. Lupins could potentially be a valuable fodder crop but they are toxic to many animals. Fortunately there are a number of lupin species and strains which are harmless and their use of fodder is on the increase. Foxglove are potentially dangerous too although it must be admitted that their unpleasant flavour would quickly repel a would-be eater.


Insects of course are happy with laburnum. I have - just once - found the Gorse Shieldbug, Piezodorus lituratus, on laburnum, although I find it regularly on gorse in the Daventry area. 

The Gorse Shieldbug is one of our largest shieldbugs.

Ah, if only I had a larger garden...

Laburnums at Bodnant.