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The largest Syringa in our northern gardens, where plants thirty feet 
high and correspondingly broad are sometimes found, appears to be a 
hybrid between P. coronarius and some unrecognized species. To this 
plant, whose history is unknown, the name of Philadelphus maximus 
has been given. Another hybrid called Philadelphus splendens appeared 
in the Arboretum several years ago and is supposed to be a hybrid be- 
tween two American species, P. inodorus and P. pubescens. It is a 
large and shapely shrub with pure white, only slightly fragrant flow- 
ers an inch and three-quarters in diameter and borne in erect clusters. 
This hybrid is a free-flowering plant and when the flowers are open it 
is the showiest plant in the Syringa Group. 
These early hybrids are the result of natural cross fertilization, and 
the systematic breeding in the genus dates from the time that Lemoine 
first crossed the Rocky Mountain P. microphyllus with P. coronarius 
and produced a plant to which he gave the name of P. Lemoinei. 
Lemoine then crossed his P. Lemoinei with P. insignis and produced a 
race to which the general n^me of P. polyanthus has now been given. 
Well known forms of this plant are “Gerbe de Neige” and “Parvillon 
Blanc.” To another race of the Lemoine hybrids the name of Phila- 
delphus cymosus has been given. This race was obtained by crossing 
P. Lemoinei and P. pubescens or some related species. “Conquete” is 
considered the type of this group. Other well known plants which are 
said to belong here are “Mer de Glace,” “Norma,” “Nuee Blanche,” 
“Rosace,” “Voie Lactee” and “Perle Blanche.” Another race of hy- 
brids with double racemose flowers raised by Lemoine and of doubtful 
origin is called P. virginalis. The type of this group is Lemoine's 
“Virginal.” Other plants referred to it are “Argentina,” “Glacier,” 
and “Bouquet Blanc.” 
Late Viburnums. The Arboretum in late June owes much beauty to 
several species of Viburnum which have been planted generally in road- 
side and border plantations. The handsomest of these plants is Vibur- 
num cassinoides, an American species which, although it grows natur- 
ally in cold northern swamps, is improved by cultivation and in ordinary 
garden soil is a handsomer and more shapely plant than in its natural 
form where it often makes straggling stems from fifteen to twenty 
feet tall. The beauty of this Viburnum is in its ample, thick and lust- 
rous leaves which vary greatly in size and shape on different plants, 
in its broad convex clusters of pale cream-colored flowers, and in its 
large and showy fruit which when fully grown is yellow, then pink and 
finally blue-black, the three colors often appearing at the same time 
in the same cluster. Not often before has this Viburnum been as 
thickly covered with flowers as it is this year. The fruit is larger than 
the bright blue fruit of the other summer-flowering American species. 
Viburnum dentatum, V. venosum and V. Canbyi which bloom in the 
order in which they are mentioned here; and few plants respond more 
to generous treatment with vigorous growth, improved habit and hand- 
somer foliage. The largest as well as the latest flowering of these 
plants, V. Canbyi, will not be in bloom for two or three weeks. Vi- 
burnum dentatum, a Japanese red-fruited plant, also flowers a little 
later than Viburnum cassinoides. It is a large, broad, and perfectly 
hardy shrub with wide flat clusters of flowers which are followed by 
