18 Proceedings of the Royal Irish Academy. 



purpose. This has long been the case, as Parsons, the well-known uursery- 

 mau at Flushing, Ohio, wrote in 1877, that " it is vastly inferior to the London 

 Plane in outline, durability, and health." 



P. fflahmta, Fernald (1901), appears to be a form of P. ocndenfalis occur- 

 ing in north-eastern Mexico, with more pubescence than usual persisting on 

 the petiole and under surface of the leaf. 



?<. Platanus acerifolia, AVilld. London Plane. 

 Plate VL fig. 3. 



A hybrid between P. orieiUalis and P. ocddcntalis, of which the history is 

 given above. A lai"ge ti^ee, wide-spreading in habit, with pendulous lower 

 branches. Leaves large, often 10 inches in width, usually cordate at tiie base- 

 with five distinct triangular lobes, the main nerves arising at the junction of 

 the petiole with the blade ; tomentum persistent on the petiole and main 

 nerves. In vigorous trees the terminal leaf on the branch has long lobes, and 

 the base is deeply and narrowly cordate, so that the point of attachment of 

 the petiole is not far from the centre of the whole blade. The lobes are either 

 entire in margin or with one, two, or more short teeth. Fruit-balls, usually 

 2 or 3, in some trees 2 to 6, rarely 1 ; large, 1} inch in iliameter ; bristly. 

 Achene with a short conical glabrous head and a tomentose body ; style often 

 during winter breaking ofifat a variable distance from its insertion. 



This ti-ee is very vigorous, and it produces good seed from which seedlings 

 can be easily raised ; but in nurseries it is invariably propagated by cuttings. 

 The seedlings, which are described above, are not unifonu. 



There are two planes with variegated leaves, whicli in shape resemble the 

 London Plane : — (1) \'ar. Suitnei-i, leaves large, white over most of the sur- 

 face, but the centre with green spots; and (2) Yar. aureo-vnriajata (var. 

 Kflseiinna, Schneider), leaves spotted in the centre with yellow, margin green. 



These are probably seedlings of P. actrifolui, as variously coloured sports 

 are .apt to occur iu the midst of a crop of hybrid seedlings. 



4. Platanu* hispanica, Muenchhausen (1770). 



l'iate.s IV and VII, fig. 5. 



Platanus orirntalis hi.Hjwnim, I>oudon (18:^8). 

 Platanus oceidtntnlU hispanic/t, Wesmael (1867). 

 Platanus cali/m^nica, Hort. 

 Platanus macrophijlla, Hort. 



A tree with a tall straight stem and moderately wide crown ; leaves larger 



