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herbaceous plants at Kew. Considered as part of the landscape 
this system is not beautiful, especially in the early stages, when the 
plants are not fully grown and bare spaces yet await their destined 
occupants. But for purposes of botanical study no other arrange- 
ment is so convenient. 
The collections of trees are, of course, spread over the Arboretum 
generally, the earlier natural orders (in the Bentham and Hooker 
sense) being planted at the eastern portion of the grounds near the 
Museum. A special consideration is paid to American trees that 
reach timber-producing size. With these the system is to plant 
and (second) a single specimen at a distance of not less than 100 
feet from its companion group. This is to show its value as an 
isolated tree for gardens, parks, &c. [See Plate.] 
AMERICAN THORNS. 
One of Professor Sargent’s great tasks for some years past has 
been the elucidation of the North American Crataegi. It has 
involved an enormous labour but during the course of it he and his 
co-workers have been able to introduce to cultivation many new, 
very distinct and beautiful species. A number of dwarf bushy 
— are of particular interest to planters because their low, 
almost shrubby habit makes them suitable for places where the 
older thorns, from considerations of space, could not previously be 
own. out fifteen acres on the eastern slope of Peter’s Hill 
have been devoted to the type collection of American thorns. The 
plants have been raised from the type trees of each species and 
every plant has its place defined on a plan of the site, so that, in 
case of loss of label, its identity would be recoverable. From ten 
to twenty years must elapse before this collection reaches its best, 
but it will eventually constitute probably the most remarkable 
assemblage of members of a single genus in the world. 
It was too late in the season to see the flowering of the rich and 
well-grown collection of garden varieties of lilac, but Syringa 
japonica, the noblest of the genus and a tree here over 30 feet high, 
was very striking in the profusion of its large pyramidal panicles of 
white blossom. Even with us it is a very useful small tree because 
of its late flowering, but it is one of the instances already alluded to 
where North Asiatic deciduous trees thrive much better in places 
where the summers are hotter than ours. 
One of the great annual displays of blossom in the Arboretum is 
made by Rhododendron Kaempferii, a Japanese ally of R. indicum 
but very hardy, introduced by Professor Server less than 20 years 
ago. ‘This and most of the other azaleas were past before my 
visit, but I was fortunate to find R. arborescens—an azalea native of 
the Eastern United States—tfully in flower. Its flowers are white 
with long red stamens, and its charm is heightened by a most 
EOE perfume. It is curious that it is scarcely known in British 
