96 
EASTERN SHADE TREE CONFERENCE 
“The studies that Prof. A. Henry has made in recent years of hybrid 
trees led him also to the study of the London plane. His conclusion is 
that this tree is ‘undoubtedly a hybrid and must have originated as a 
chance seedling in some botanic garden where an occidental plane 
and an oriental plane happened to be growing together.’. . . One of the 
first proofs of hybridity is in the variability of the seedlings of the London 
plane (slide), a well established characteristic of the seedlings of a first 
cross (F 2’5). This variability is to be noted in the size and depth of lobing 
of the leaves, in the number of fruit balls on a stem and in the characteris¬ 
tics of the individual fruits (achenes) that make up these balls, all more 
or less intermediate between those of oriental plane and American plane. 
Prof. Henry makes a very interesting attempt to show that the 
London plane possibly originated at the Botanic Garden of Oxford 
about 1670. The younger Bobart, who became curator of the garden 
in 1680, compiled a manuscript list of the trees and shrubs there, which 
was printed by Messrs. Vines and Druce in 1914. In this list three 
planes are included, viz., Platanus orientalis , P. occidentalism and one 
which Bobart distinguished as P. inter orientalem et occidentalem media. 
And in the Sherard Herbarium at Oxford there is a dried specimen (No. 
476) corresponding to this diagnosis, and labelled “ Platanus media” 
which Prof. Henry says is undoubtedly the London plane. Additional 
evidence is also found in the British Museum, where is preserved the type 
specimen of Plukenet, used by him in his (the first) published descrip¬ 
tion of P. acerifolia in 1700, also two fine leaves of this tree, collected by 
Petiver, and labelled “ Platanus media n.d. Bobart, Ox.” There seems 
to be no doubt then that the London plane was growing at Oxford late in 
the seventeenth century, and as Plukenet described it as bearing large 
fruit balls in 1700, it was at that time probably some thirty years old. 
Moreover, this is the earliest extant evidence of the existence of the 
London plane.” 
Another evidence of the hybrid nature of the tree which we call the 
London plane is its remarkable adaptability. Like the mule, the well- 
known animal hybrid of horse and jackass, it endures harsh treatment all 
its life without flinching, and yet makes a better showing under adverse 
conditions than either of its parents. On the block where I live in 
Brooklyn are pin oaks, Norway maples and one London plane. The 
much vaunted pin oaks and Norway maples look pretty tired by August, 
with frayed, discolored leaves and slight yearly growth, while the London 
plane, with the same environment, is as green and vigorous as if it were 
