LABURNUM, known botan ically as Laburnum vulgare (or Cytisus Laburnum), a familiar tree of the pea family (Legu minosae) ; it is also known as "golden rain." It is a native of the mountains of France, Switzer land, southern Germany, northern Italy, etc., has long been culti vated as an ornamental tree throughout Europe, and was intro duced into north-east America by the European colonists. Gerard records it as growing in his garden in 1597 under the names of anagyris, laburnum or beane trefoyle.
Several varieties of this tree are cultivated, differing in the size of the flowers, in the form of the foliage, etc., such as the "oak leafed" (quercifolium), pendu lum, crispum, etc. ; var. aureum has golden yellow leaves. One of the most remarkable forms is Cy tisus Adami, which bears three kinds of blossoms, viz., racemes of pure yellow flowers, others of a purple colour and others of an in termediate brick-red tint. The
last are sterile, with malformed ovules, though the pollen appears to be good. The yellow and purple "reversions" are fertile. It originated in Paris in 1828 by M. Adam, who inserted a "scion" of the bark of Cytisus purpureus into a stock of Laburnum. A vigor ous shoot from this bud was subsequently propagated. For the nature of other so-called graft hybrids, see CHIMAERA.
The laburnum has highly poisonous properties. The roots taste like liquorice, which is a member of the same family as the labur num. It has proved fatal to cattle, though hares and rabbits eat the bark of it with avidity. The seeds also are highly poisonous.
The heart wood of the laburnum is of a dark reddish-brown colour, hard and durable, and takes a good polish. Hence it is much prized by turners, and used with other coloured woods for inlaying purposes.