is found only in regions of comparatively mild winters, is perfectly hardy 
in New England in the most exposed positions, while native plants and 
others from much colder regions have suffered severely during the past 
winter. The American Smoke-tree is as much at home in western Europe 
as it is in New England, although usually the trees and shrubs of the 
southeastern United States do not flourish in Great Britain where they 
miss the summer and autumn heat necessary to properly ripen their wood. 
The Mock Oranges (Philadelphus) are fast coming into bloom, and sev- 
eral of them will be in flower during the present week. They can be 
found in the Shrub Collection and in the large supplementary collection 
on the right-hand side of Bussey Hill Road opposite the Lilacs. Those 
which deserve particular attention now are Philadelphus inodorus, a na- 
tive of the southern Appalachian region, with large solitary pure white 
flowers, and, although still little known one of the most distinct and beau- 
tiful of the genus; Philadelphus Falconeri of unknown origin, but prob- 
ably a native of China and Japan, as it was sent to the Arboretum many 
years ago from the Parsons Nursery on Long Island where many eastern 
Asiatic plants were first cultivated in this country; Philadelphus maxi- 
mus , a hybrid between two American species and the largest of all the 
Mock Oranges. In old gardens near Boston this plant has sometimes 
grown to the height of thirty feet. Philadelphus Lemoinei is also in 
flower. This is the result of a cross between the common Mock Orange 
of gardens, the European Philadelphus coronarius , and the small-flow- 
ered and small-leaved Philadelphus microphyllus of the Rocky Mountains 
of Colorado. This cross was made by Lemoine of Nancy, the most suc- 
cessful of hybridizers, who had received the Colorado plant from the 
Arboretum, and it was the beginning of a race of dwarf garden shrubs 
produced by Lemoine which have few equals in beauty. Philadelphus 
microphyllus itself will not expand its fragrant flowers for several days, 
but many of its progeny are now beginning to flower. Some of the most 
interesting of these are the varieties known as Avalanche, Boule d’Ar- 
gent, Boquet Blanc, Candelabre, Conquete, Fantasie, Gerbe de Neige, 
Manteau d’Hermine, Mont Blanc, Nuee Blanche, Pavilion Blanc, and sev- 
eral others. 
The last of all the Hawthorns to bloom is just opening its buds. This 
is the so-called Washington Thorn, Crataegus cor data, a native of the 
southern Appalachian foothills and the region westward to Missouri. It 
is a tree sometimes thirty feet high with erect branches, small, nearly tri- 
angular, shining leaves which turn bright scarlet in the autumn, small, 
dull white flowers in small compact clusters, and small scarlet fruit which 
remains on the branches with little less color until spring. The late flow- 
ers, the brilliancy of the autumn foliage and the abundance and bright- 
ness of the fruit during the winter months make this one of the most 
desirable of the American Hawthorns as a garden plant. The leaves are 
not destroyed by the leaf-mining caterpillars which make the foliage of 
many American Hawthorns look in early summer as if they had been 
scorched by fire; its only drawback is the brittleness of the branches 
which are sometimes broken down by the weight of snow. Several large 
plants of the Washington Thorn can be seen on the slopes of the overlook 
near the top of Bussey Hill. 
The flowers of the Laurel (Kalmia) are at their best and should be seen 
this week. They can be most easily reached from the South Street and 
and from the Walter Street entrances. 
The Arboretum will be grateful for any publicity 
given these Bulletins. 
