England many years ago between M. glauca and the American Um- 
brella-tree, M. tripetala. It has leaves like the leaves of M. glauca, 
which it also resembles in the perfume of the cup-shaped pure white 
flowers intermediate in size between those of its parents. Unlike many 
hybrids which are usually hardier and more vigorous than their parents, 
M. Thompsoniana is less hardy than either M. glauca or M. tripetala, 
and sometimes has been killed to the ground in severe winters. The 
latest of the Magnolias, M. macrophylla, now covered with buds, is still 
to flower. This handsome tree is interesting for it has larger leaves and 
larger flowers than any other plant of the northern hemisphere beyond 
the tropics. A native of the south from North Carolina to Louisiana, 
it is perfectly hardy here; it is best planted, however, in sheltered 
positions as the leaves are easily torn and disfigured by the wind. These 
Magnolias are on the right-hand side of the Jamaica Plain entrance 
east of the Administration Building. 
On the Administration Building a plant of the Japanese climbing Hy- 
drangea ( H . petiolaris) is now in flower. In the country this plant is 
usually seen climbing up the trunks and spreading over the branches of 
trees, but it has been found capable of attaching its stems firmly to 
brick-work and therefore to be useful in covering walls and buildings. 
The bright green foliage makes a handsome contrast with the broad 
heads of flowers which are surrounded by a row of neutral ray flowers 
of medium size. Two shrubby Hydrangeas will soon be in flower in' the 
Shrub Collection, H. Bretschneideri from northern China and its variety 
setchuenensis from western China. The former is an old inhabitant of 
the Arboretum and is a tall, free-flowering shrub well worth a place 
in all collections. The variety which is less well known appears to be 
perfectly hardy and equally free-flowering. 
Some of the earliest of the large collection of Mock Oranges (Phila- 
delphus) are already in bloom. The earliest this year is Philadelphus 
hirsutus of the southern Appalachian region, a tall shrub of rather 
open habit, with small flowers and of no great ornamental value. The 
Korean form of P. Schrenkii (var. Jackii ), a plant of columnar habit and 
the European P. coronarius, the Mock Orange of all old-fashioned gar- 
dens, are also in bloom. Of the latter there are in the collection a dwarf 
form which does not often bloom, a form with yellow leaves and one 
with very narrow leaves (var. salicifolia), a distinct and interesting plant. 
Other interesting plants now in flower in the Shrub Collection are 
the Chinese Cotoneaster hupehensis, with white flowers which are show- 
ier than those of the other species of the genus, and make the plant 
look like a Spiraea, Indigofera Kirilowii from Korea, with pink flow- 
ers, Genista germanica, and Spiraea bracteata from Japan, a large 
shrub with long arching branches and one of the handsomest of the 
still little known Spiraeas, Lonicera Ledebourii is still in good condi- 
tion, and L. Kirilowii amoena is only just now dropping its lovely 
pink flowers. 
This bulletin will reach its Massachusetts readers at a time when a 
visit to the Arboretum will repay all lovers of flowers for the Laurels 
(Kalmias) will be in bloom at the base of Hemlock Hill. 
The Arboretum will be grateful for any publicity 
given these Bulletins. 
