10 Proceedijigs of ihe Eoi/al Irish Academy. 



been found to surpass all other trees in its powers of resistance to drought, 

 smoke, and other unfavourable conditions of soil and atmosphere. In the 

 cities of New England, Ohio, Pennsylvania, etc., the London Plane is much 

 more successful as a street tree than the Western Plane, notwithstanding the 

 fact that the latter is the finest and largest native broad-leaved tree in the 

 forests of these states. The selection as a street tree of the London Plane in 

 preference to the native species in the regions where the latter flourishes, 

 depends on the ^^gour inherent in the foi-mer tree on account of its hybrid 

 origin. 



The London Plane, being undoubtedly a hybrid, must have originated as a 

 chance seedling in some botanic garden, where an Occidental Plane and an 

 Oriental Plane happene«i to be growing close together. Such a seedling, by 

 the vigour of its growth and the novelty of its foliage, would attract atten- 

 tion and l»e propagated by an observant gardener. The ease with which the 

 London Plane can be raised from cnttings would much facilitate its propaga- 

 tion. I shall try to show that it possibly originated in the O.xford Botanic 

 Garden abo\it 1670, though this surmise cannot be definitely proved. 



l"he Occidental Tlaue was introduced from America into England by 

 Tradescant in 1636, about a century later than the earliest record of tlie 

 Oriental Plane in this country. By 1670, there would have been trees of the 

 American species old enough to bear pollen. The connexion with Oxford is 

 as follows: — Jacob liobart, junior, who succeeded his father as curator of the 

 Botanic Garden at Oxford in 1680, left in MS. an "Enumeration of Trees and 

 Shrubs,"' in which for the first time there is mention in any record of the 

 London Plane, This MS. is unfortunately without date ; but a similar MS. has 

 1666 on the fly-leaf. In the " Enumeration " the planes in cultivation are 

 di8tinguishe<l as follows: — 



No. 475. Platanus orientalis, pilulis amplioribus. 



No. 476. P. inter orientalem et occidentalem media. 



No. 477. P. occidentalis aut virginiensis. 



Corresponding to the diagnosis. No. 476, of the London Plane, as inter- 

 mediate between the Oriental and the Occidental species, there is a dried 

 specimen, undoubtedly P. aceri/olia, in the Sherard Herbarium at Oxford, 

 labelled "Platanus media," 



The first published description of the London Plane was by Plukenet in 

 1700, in his " Mantissa," p. 153, which reads as follows :— " Platanus orientalis 

 et occidentalis mediam faciem obtinens, Americanus, globulis grandioribus, 

 foliis splendentibus atris." The type specimen of this description is in the 



■ This U printed by Vin«s and Druce, " Account of Morriaonian Herbarium," p. 261 

 (1914). 



