1921-22.] BOTANICAL SOCIETY OF EDINBURGH 85 



say, and on the Laburnum stem near where the bud had 

 failed there appeared a strong shoot whicli bore narrow 

 leaves distinctlj' difterent from the leaves of the Laburnum 

 stock and resembling the smaller and narrower leaves of 

 C ptcrpureus. This shoot was allowed to grow, and eventu- 

 ally it bore flowers in racemes of a dull pink colour. Grafts 

 from this strange development weremade on other Laburnum 

 stocks, and these as the}^ developed preserved the habit and 

 flowers of the original " Graft Hybrid." 



Not uncommonl}' some of the branches of this graft 

 hybrid revert to the original forms from which the hj^brid 

 is supposed to be derived, and so there comes about the 

 curious development of the same tree bearing three kinds 

 of flowers and foliage. This peculiarity had developed on 

 Mr. Adam's original budded tree, a development which is 

 maintained in most of the trees raised from C. Adaini by 

 grafting. 



Some fifteen or twenty years ago, when I was planting 

 a few flowering shrubs I included among them the pink 

 Laburnum, G. Adami. It was then all pink flowered, but 

 a few years later it showed the yellow- flowered branches, 

 the original Laburnum of the stock breaking out, and it 

 has now broken out very largely in spite of much pruning. 

 Only in the last year or two are there small pieces of the 

 purple Cytisus appearing on my tree, but not to anj^ extent. 



This is all preliminary, and I come back to Professor 

 Weiss's most interesting lecture. When dealing with C. 

 Adami he explained, what I had already found out, that 

 the pink racemes are almost invariably barren, none of the 

 seed pods filling up. He further explained that when the 

 seed of the yellow-flowered portions are planted the result- 

 ing trees are always just the yellow Laburnum, and in fact 

 all seedlings from C. Adami that have so far been recorded 

 are of the pure yellow type. 



Having failed to find aii}^ seed of the pink flowers, 

 which I frequently looked for, I thought I would ti-y to 

 see what was produced from a handful of w^ell-filled pods 

 from the yellow portion of my C. Adami. I think about 

 forty seeds were sown, and I was rather pleased to find 

 that one of the seedlings had the smaller and narrower and 

 the somewhat darker leaves of the pink-flowered part of 



