small and uninteresting. Next to it in the Shrub Collection there is a 
specimen of the form of this species from western China, the var. podo- 
carpa, which is in every way a less desirable garden plant. 
In the fourth of these bulletins attention was called to Diervilla prae- 
cox, a native of Japan. Some of the hybrids of this plant raised in 
France are now flowering in the Shrub Collection. Hardier than some of 
the other garden races of Diervilla, these are valuable for the spring 
gardens. The handsomest variety in the collection is perhaps the one 
called Le Printemps; other varieties now in flower are Gracieux and Con- 
querant. 
The Deutzias are generally not very satisfactory garden plants in this 
climate, and several of the species and varieties suffer here from the cold 
of severe winters. The exception is a hybrid between the Japanese 
Deutzia gracilis and Deutzia parviflora from northern China, called 
Deutzia Lemoinei for the great French hybridizer by whom it was pro- 
duced a few years ago. This plant resembles Deutzia gracilis, but it 
grows into a taller and broader shrub, and the flowers are larger. It is 
certainly one of the best garden plants of recent introduction. With the 
other species, varieties and hybrids which are grown here it can be seen 
in full flower in the Shrub Collection. The number of Chinese species of 
Deutzia is now known, largely through the investigations of the Arbore- 
tum, to be thirty-two, although twenty-five years ago only five Chinese 
species had been described. Many of these new species are now growing 
in the Arboretum nurseries, but it is too soon to speak of their value as 
garden plants. 
Spiraea Van Houtii is a hybrid raised in Europe between Spiraea can- 
toniensis, a rather tender Chinese species, and Spiraea trilobata of Sibe- 
ria. It is easily propagated and grows rapidly into a tall broad shrub, 
and has been largely advertised and distributed in recent years. It suf- 
fers, however, in cold winters and is less valuable than Spiraea trilobata , 
which is a dwarfer plant with spreading and pendant branches, and is 
perfectly hardy and as free flowering as its offspring. Although first 
brought to this country at least eighty years ago, Spiraea trilobata is 
now rarely found in American gardens. These two Spiraeas can now be 
compared in the Shrub Collection where they are in flower side by side, 
and where there are many other species of this genus. 
Enkianthus is an eastern Asiatic and Himalayan genus, with drooping 
clusters of small, bell-shaped flowers, and dry capsular fruits, and is re- 
lated to Andromeda. Three Japanese species are well established in the 
Arboretum and can be seen in the Shrub Collection and in a large group 
on the right-hand side of Azalea Path. The handsomest of the three 
species, Enkianthus campanulatus , is a tall shrub with slender erect 
stems and branches, and light yellow or rose-colored flowers. It is found 
in every Japanese garden where it is valued for the bright scarlet color 
the leaves assume in autumn, and where it is often cut into balls and 
other fantastic shapes. This Enkianthus is a garden plant here of real 
value. The other species, Enkianthus japonicus and Enkianthus sub- 
sessilis, are smaller plants with smaller yellow flowers and are less valu- 
able ornaments of the garden. 
Roses are already beginning to flower. The earliest in the Shrub Col- 
lection is Rosa cinnamomea, the old-fashioned Cinnamon Rose. A more 
beautiful plant now in flower in the Shrub Collection is a Siberian form 
of the so-called Scotch Rose known as Rosa spinosissima var. altaica. 
