Platanus 627 



PLATAN us OCCIDENTALIS, Western Plane, Buttonwood 



Platanus occidentalis, Linnaeus, Sp. PL 999 (1753); Loudon, Arb. et. Frut. Brit. iv. 2043 (1838) 

 (in part); Sargent, Silva N. America, vii. 102, tt 326, 327 (1895), and Trees N. Amer. 344 



(1905)- 

 Platanus lobata, Moench, Meth. 358 (1794). 

 Platanus hybridus, Brotero, Fl. Lusit. ii. 487 (1804). 

 Platanus vulgaris, c. angulosa, Spach, Ann. Sci. Nat. xv. 291 (1841). 



A tree, attaining in America a height of 170 feet and a girth of 35 feet. Bark 

 furrowed near the base of large trunks into broad rounded scaly ridges, higher on 

 the tree separating in large thin scales, exposing irregular surfaces of pale-yellow 

 or whitish inner bark. Branchlets and buds indistinguishable from those of 

 P. orientalis. 



Leaves (Plate 204, Fig. 2) large, about 8 inches broad by 7 inches long, broadly 

 ovate, obsoletely three- to five-lobed, the lobes much less marked than in P. acerifolia, 

 not reaching to one-third the length of the blade, separated by very broad and very 

 shallow sinuses, entire or with long acuminate teeth ; base widely cordate or truncate, 

 with often a slight cuneate part decurrent on the petiole. 



Fruiting heads solitary ^ at the end of a glabrous stalk (3 to 6 inches in length), 

 about an inch in diameter, not bristly, but smooth, the persistent styles being 

 minute or obsolete. Achene truncate or rounded at the apex, which has a central 

 depression bearing the short remains of the style, glabrous on the body, surrounded 

 by a ring of long stiff hairs arising from the base only. 



This species differs from all forms of P. orientalis in the solitary fruiting head, 

 composed of glabrous achenes, with only a basal ring of long hairs. The foliage is 

 nearest to P. acerifolia, but differs in the obsolete ill-defined lobes. (A. H.) 



Distribution 



According to Sargent the western plane grows on the borders of streams and 

 lakes in rich alluvial soil, and is widely distributed throughout the eastern half of the 

 United States, crossing into Canada, where it is confined to the northern shores of 

 Lake Ontario. In the United States it extends from South-Eastern New Hampshire 

 and Northern Vermont southward to Northern Florida, Central Alabama, Mississippi, 

 and Texas, as far cis the valley of the Devil's River ; and westward to Eastern 

 Nebraska and Kansas. It attains its largest size in the bottom-lands of streams in 

 the basins of the lower Ohio and Mississippi rivers. 



The buttonwood, or sycamore, as it is often called in the United States, is the 

 most massive, if not the tallest, deciduous tree of North America. The younger 

 Michaux'' states that his father measured, on an island in the Muskingum valley, a 

 "palm-tree or Platanus occidentalis" 40 feet 4 inches in girth at 5 feet. The same 



' Sargent in a letter to Kew, dated 1884, states that he had received from three different collectors specimens showing 

 two heads on the peduncle ; but this is rare and abnormal. 

 2 Travels in the Alleghanies, 86 (1805). 



Ill 2 A 



