graves: breeding trees for disease resistance 
95 
This Department intends to continue with its shade tree planting 
program as rapidly as funds permit. It will be guided by the lessons 
learned from the results of the storm. Even greater attention than 
formerly will be centered on the selection of species, and all due con¬ 
sideration will be given to the planting sites, so that every opportunity 
may be allowed the trees to grow into strong, healthy, mature specimens, 
capable of withstanding the ravages of wind and drought. 
Tree planting must be continued, even on a larger scale than formerly, 
if this generation is to pass on to future generations their just heritage of 
tree lined roads. 
BREEDING TREES FOR DISEASE RESISTANCE 
By Arthur Harmount Graves, Curator of Public Instruction , Brooklyn 
Botanic Garden , New York 
Several months ago I was speaking on “Shade Trees” to a New York 
audience—a garden club—and tried to make clear the fact that the 
very popular plane tree now and for many years past planted commonly 
along the streets in all the boroughs of New York City as well as through¬ 
out the country in general, is a hybrid —the London plane—and not the 
oriental plane, as it seems to be usually called. I tried to explain care¬ 
fully that this form of plane tree has probably resulted from a cross 
pollination of the common native buttonball, Platanus occidentalism or 
sycamore, as the U. S. Forest Service would have us call it, and the 
oriental sycamore, Platanus orientalis. Then I was astonished to hear 
the gentlemen who followed me on the program continue to call the 
tree (which of course everyone knows, since it is one of the best shade 
trees for large cities) the oriental plane. This must have been either 
because they had not heard me, or because they were not convinced. 
Apparently, the wrong name (oriental plane) is so firmly rooted that it 
would take nothing less than a hurricane to overthrow it. 
In my outdoor tree classes, for more than 20 years past, I have tried 
carefully to show that the tree is a hybrid, and to make this plain have 
pointed out its resemblances now to one and now to the other parent. 
Not being, by training, a taxonomist, I would not dare to do, or rather 
to say all this on my own initiative. Mr. Alfred Rehder, of the Arnold 
Arboretum, and Dr. Leon Croizat of the same institution, stand back of 
me. 
What are the facts? In Gardener’s Chronicle for July 26,1919, in an 
article entitled “The London Plane,” (p. 47) we read the following: 
