220 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



In connexion with the same question is the curious phenomenon 

 of what would appear to be dying or disappearing races which at 

 the present time are represented only by a solitary species in China, 

 and by another one, equally solitary, in East America. There are 

 the two Liriodendrons or Tulip-trees, for instance. The American 

 Tulip-tree, so well known and admired in this country for over two 

 hundred years, is not only one of the most magnificent deciduous 

 trees of the globe, being 190 feet high in the Southern Alleghanies ; it 

 was, until 1875, distinct from every other known tree. In that year 

 the Chinese Tuhp-tree was discovered, and now, thanks to Wilson, 

 we have it in our gardens. It is not, apparently, so fine a tree as the 

 American one, for it has not yet been found over 100 feet high, but 

 it is remarkably similar to it. 



A second instance is provided by the genus Cladrastis. From 

 eastern North America was long ago introduced that beautiful tree 

 we know as " yellow wood " [Cladrastis tinctoria or Virgilia lutea). 

 Until about twenty years ago it was regarded as monotypic, but in 

 1901 Wilson sent home from China another species, Cladrastis 

 sinensis, which is thriving well in our gardens. Judging by dried 

 material, it is very handsome in flower. Wilson has, indeed, described 

 it as one of the most beautiful of all Asiatic trees. 



Most of you will know, at any rate by repute, the Sassafras of 

 North America. I am afraid it is now rather uncommon with us, 

 although H.R.H. the Duchess of Albany has a splendid tree, 70 feet 

 high, at Claremont. Its spice-scented, curiously shaped leaves 

 make it a very distinct and interesting tree, until lately quite unique 

 in gardens. Henry, however, found another species in China, 

 as solitary there as its ally is in Eastern America. Wilson intro- 

 duced it, and a few plants are now in cultivation. 



Several other of Wilson's discoveries and introductions might 

 be mentioned that further illustrate this curious inter-continental 

 relationship. He has, for instance, found a new Symphoricarpos, 

 a genus hitherto only known to us by the North American species. 

 Amongst them were the well-known * Snowberry ' and the red- 

 fruited Symphoricarpos orbiculatus. But this new Chinese species, 

 now in cultivation, is described as having blue fruits. I 



Then there is the interesting genus Nyssa, to which the tree | 

 popularly known as Tupelo belongs — one of the best autumn-colouring | 

 trees we have. This genus was long thought to be exclusively confined I 

 to the south-eastern United States, but Professor Henry discovered, 

 and Wilson has introduced, another species from China — Nyssa 

 sinensis. 



Owing to Wilson's labours, some of our most important groups 

 of trees and shrubs have been very much augmented, and their 

 importance in gardens much increased. Most striking of them all pro- 

 bably is Rhododendron. For many years after Sir Joseph Hooker's i 

 travels in Northern India, the Himalaya was regarded as the head- j 

 quarters of this genus. The exploration of China, however, has 



