324 
THE GARDENING WORLD 
April 16. 1904. 
quite independently of any bad pruning that may be. given 
them. There is less necessity for pruning, however, in the 
United States, with their wide streets, than here. 
Reference to the list of trees grown in Ithaca itself gives us 
an insight into the kind> employed and their nature. The 
largest number of any one tree planted in this city is 2,105 
Sugar Maples, of which 1,574 are in good condition. The 
American Elm comes next in point of numbers with 1,625 
trees, of which 1,569 are in good condition. The White 
Willow (Salix alba) is represented by 602 trees, of which 558 
are good. The Horse Chestnut comes next, being represented 
by 450 trees, of which 431 are good. All other species of 
trees are represented by much smaller numbers, often only by 
a single tree. Several Conifers have been employed, including 
the red Cedar, American and European Larches, and the 
Norway Spruce. The most singular thang about these Spruces 
is that of sixty-one trees sixty of them are stated to- be good. 
In the time of the late J. C. Loudon London possessed 
numerous coniferous trees, many cf which consisted of the 
Scotch Fir. They were not even in his day an entire success, 
and he advised the planting of other kinds of trees. Since 
then only a few straggling specimens of this Conifer may be 
seen on the outskirts of London, with a few Cedars of Lebanon, 
most of which are gradually dying where they happen to be 
old. 
Not all of the American cities are planted on the same plan 
as Ithaca, as there are some striking exceptions at Washing¬ 
ton, the capital. Here about 80,000 shade trees have been 
planted, and the annual upkeep of these is 20,000 dollars. Of 
the several species of trees employed at Washington we are 
most interested in the Ginkgo- Avenue. The trees are cer¬ 
tainly of no great age as yet, being only twenty-three years 
old, but. they are of beautiful pyramidal shape, and have never 
been pruned. The effect produced in autumn must be very 
handsome when the leaves are of a uniform soft yellow. The 
tree is a Conifer allied to- the Yew, and is notable for its leaves, 
which considerably resemble those of the pinnae of an Adian- 
tum. It has been well known that this tree will thrive even in 
London, but very little if any use of it has ever been made 
for the purpose of street planting. 
Mention of the Maidenhair tree in Washington takes us ta 
Paris, where Ailanthus glandulosa or Tree of Heaven forms 
such a conspicuous feature on some of the streets, but espe¬ 
cially on the Boulevard Mont Pamasse, where the trees form 
a fine avenue, and are of some considerable height and width. 
The foliage of this tree has a beautiful feathery or Fern-1 ike- 
appearance, and under certain forms of treatment has quite a 
sub-tropical effect. We have evidence that it will succeed in 
London wherever the space is wide enough for the accommoda¬ 
tion of a fair-sized head. In no city, perhaps, are the trees in 
cleaner and uninjured condition than in Paris, but in the city 
itself they are of no great size and would pro-bably date from 
the making of the boulevards and the comparatively recent 
improvements of the city. At 4 ersailles, however, where 
there are old Elms, they have been suffering greatly from 
insects, just as much as in the case of the- old Elms in the 
London parks. 
The cities of Germany are characterised by haidier and 
much more common trees, in accordance with the much 
colder climate in winter. Some of the most conspicuous treed 
are Lindens or Limes, Sycamores, Norway Maples, Silver 
Maples and Oaks. The latter are young trees which have 
been recently planted in the Deutscher Ring, Cologne. It is 
significant, however, that these are in a flourishing condition. 
Not manv weeks ago we suggested Oak trees for some of 
the streets'of London, on account o-f their slow growth and 
great durability, as well as because they are amenable to 
pruning to keep them within any prescribed limits. The lay 
Press in several instances took up our suggestion and made 
some remarks about the use of the British Oak for London 
streets. . . . 
The Metropolitan Public Gardens Association ^U^OhS 0. t 
a dozen Oaks, including the Turkey Oak, with some of its 
varieties and hybrids, together with Quercus rubra and Q, 
tinctoria, two North American species. No mention is made 
however, of the British Oak, which, although the leaves are 
perhaps less ornamental, the trees would lie equally useful and 
would perhaps succeed, better than the Turkey Oaks, but 
particularly those of a semi-evergreen character. For the 
cleaning of the streets it would be convenient if the leaves 
were to come down altogether early in November. This would 
also be better for the trees themselves, as our atmosphere after 
that time becomes veiy filthy. 
In passing, we may remark that Limes and other hardv 
trees are also a feature of the principal Russian cities, because 
they are capable of withstanding the low temperatures that 
occur in winter. The Oriental Plane and the Olive are more 
characteristic of cities bordering on the Mediterranean. Me 
may also remind our American cousins that Oriental Svca- 
more is hardly a correct term to apply to the London Plane 
(Platanus acerifolia). 
The list of trees suitable for London and its suburbs advo¬ 
cated by the Metropolitan Public Gardens Association is a 
veiy good one so far as it goes, but it has defects, as the 
association is no doubt well aware. For instance, we think 
that the common Lime is quite as frequently planted in the 
streets of London and in populous places in the suburbs quite 
as often as it should be. It is a tree that always loses its 
leaves by August or September in very dry seasons. In 1893, 
when the diy weather set in in March and kept o-n through the 
spring,- the Lime trees were almost completely bare on Kew 
Green before the end of June. After rain those trees made a 
struggle and put forth some fresh leaves, but they looked 
ragged for the remainder of the season. For this reason the 
streets shc-uld not be overdone with Lime trees, a-s they are 
kept in a litter with the fallen leaves, besides which the trees 
lose in effectiveness. 
The association advocates the planting of at least four 
Willows, including three British ones, but we are not quite 
certain what they mean by Salix russelliana, which is a very 
doubtfully distinct tree from S. fragilis and S. viridis, to both of 
which the name has been applied. They mention eight species 
or varieties of Poplar that are suitable for planting, but they 
have discovered that- two Poplars that are suitable are not 
obtainable in the nurseries, and they inte-nd to foster or en¬ 
courage the propagation of the same for street planting. They 
seem to think it is only one tree, which they name P- nigra 
betulaefolia or P. trepida, These are really two Poplars, the 
first one being a- variety of the Black Italian, which succeeds 
very well in various parts of London. P. trepida is more 
correctly described as P. tre-muloides, a North American 
species similar to ours, but known as the American Aspen. 
These two trees, we have no- doubt, would grow as freely as 
any of the other Poplars grown in the streets and gardens of 
London. The first-named should be a small-leaved -form of 
the black Poplar, and P. tremuloides would be interesting and 
beautiful as a -small tree, but it is too- low-growing to be suit¬ 
able for planting at the sides of streets, and could not be 
reckoned as a shade tree. Parks and gardens or pleasure 
grounds are really the places for the Aspens. 
Selaginella watsoniana. 
(See Supplement.) 
Judmno- from the habit and structure of the branches of 
is Selaginella, it is closely allied to S. Martensii, if indeed it 
, not a mere variety of that very variable and polymorphic 
ecies. The structure of the branches is veiy similar to that 
S. M. robusta variegata, but they are dwarfer and more 
reading than that well-known garden form. They are closely 
negated all over with silvery white, so that a well-giown 
.n of it makes a handsome subject for the greenhouse or stove 
re accompanying supplement will give an idea of the ha in 
the plant. This was prepared from a photograph takerii 
e Trinity College Botanic Gardens, Dubhn, where _ ‘ 
own under the care of F. W. Burbidge, E^q., * •, 
