LaburnumBotanical Name: Cytisus Laburnam (LINN.)
Family: N.O. Leguminosae Synonym: Yellow Laburnurn.
Part Used: Seeds.
The Laburnum, indigenous to the higher mountains of Europe, is cultivated throughout the civilized world for its flowers, which appear early in the spring, in rich, pendent, yellow clusters.
All parts of the plant are probably poisonous and children should be warned never to touch the black seeds which contain this highly poisonous alkaloid, as cases of poisoning after eating the seeds have been frequent.
The Laburnum is a native of the mountains of France, Switzerland, and southern Germany, where it attains the height of 20 feet and upwards. It was introduced into England previously to 1597, at which time Gerard appears to have grown it in his garden under the names of Anagyris, Laburnum, and Bean Trefoil.
The heart-wood is of a dark colour, and though of a coarse grain it is very hard and durable, will take a polish, and may be stained to resemble ebony. It is much in demand among turners, and is wrought into a variety of articles which require strength and smoothness.
Cytisus purpurascens (Fr. C. d'Adam), the PURPLE LABURNUM, is a hybrid between C. Laburnum and C. purpureus. It was originated in Paris in 1828, by M. Adam, and has since been much cultivated in England. A curious result of hybridizing appears in this variety occasionally. The branches below the graft produce the ordinary yellow Laburnum flowers of large size; those above often exhibit a small purple Laburnum flower, as well as reddish flowers intermediate between the two in size and colour. Occasionally, the same cluster has some flowers yellow and some purple (Balfour).
Laburnum trees should not be allowed to overhang a field used as a pasture, for when cattle and horses have browsed on the foliage and pods, the results have proved deadly.
Symptoms of poisoning by Laburnum root or seeds are intense sleepiness, vomiting, convulsive movements, coma, slight frothing atthe mouth and unequally dilated pupils. In some cases, diarrhoea is very severe and at times the convulsions are markedly tetanic.
In an article on the use of insecticides against lice, by A. Bacot, Entomologist to the Lister Institute of Preventive Medicine, in the British Medical Journal of September 30, 1916, the writer records the results of experiments with various reputedly insecticidal substances, but mainly with Cytisine, the alkaloid obtained from the seeds of the Gorse and Laburnum, the physiological properties of which resemble those of Nicotine. He found that while Cytisine is quite satisfactory from an experimental point of view, its use is contraindicated, because the degree of concentration required is such as to entail risk of absorption over a wide area of the body, with almost certain toxic consequences.
Constituents: Cytisine was discovered in 1863 by Husemann and Marme, as one of the poisonous alkaloids present in the seeds of the Laburnum. It is a white, crystalline solid, of a bitter, somewhat caustic taste, with a very poisonous action. It has been recommended in whooping cough and asthma.
The same alkaloid has been isolated from the seeds of several leguminous plants. Plugge, in 1895, stated that he found it in eight species of the genus Cytisus, two of the genus Genista, two of the genus Sophara, two of the genus Baptisia, in Anagyris Joetida, and in other plants. He considered the Ulexine of Gerrard from Ulex Europaea (Linn.) to be identical with Cytisine.