Adam's Laburnum
Currently flowering in the Master’s Garden is a horticultural curiosity, Adam's Laburnum (+Laburnocytisus 'Adamii'). The tree is a graft hybrid between Common Laburnum (Laburnum anagryoides) and Purple Broom (Cytisus purpureus) and first arose in a French nursery near Paris in the 1820's.
As a graft hybrid it is not a hybrid in the true sense of the word but consists of the tissue of one plant, the Laburnum, growing within an envelope of a second plant, the Broom.
Because of this, when out of flower, the tree looks to all intents and purposes to be a Laburnum. The foliage being mostly Laburnum-like with clusters of broom-like shoots appearing occasionally, but when it flowers, its hybrid nature is revealed. The majority of the flowers are a coppery pink colour intermediate between the two parents. However, the tree will also produce some pure yellow Laburnum flowers as well as some purple Broom flowers. The proportions of these vary from tree to tree and from year to year. This year our tree, which was planted in March 2014, has just one raceme of Laburnum flowers and various odd Broom flowers, next year the proportions may well be different.