146 



AMERICAN FORESTRY 



THE UNUSUAL BARK 



The bark of the Sycamore resembles a patchwork of white, 

 green, brown and yellow. No other native tree has a similar 

 bark. 



buttonwood, and sometimes it is given the name button- 

 ball. Its scientific name is Platanus Wrightii. It seems 

 proper to call it the Southwestern sycamore for it is na- 

 tive only to the southwestern part of the United States, 

 being found chiefly in New Mexico, Arizona, and ex- 

 tending westward towards California. It attains a height 

 of 8o feet, and usually divides into several stout stems 

 near the ground. Its leaves are quite large, heart-shaped 

 at the base, and from 3 to 7-lobed. This tree is of little 

 commercial importance because of the limited amount 

 of wood that it yields, but it is one of considerable eco- 

 nomic importance since it grows chiefly on the banks of 

 streams and bordering bottomlands, and thus prevents 

 the washing away of stream banks, and makes productive 

 vast areas of wasteland that would otherwise remain 

 idle. 



The common sycamore of the eastern United States 

 is the largest deciduous tree found in the entire country. 

 In some localities it is called buttonwood, in other re- 

 gions it is given the name of buttonball, and occasionally 

 one may hear the name plane tree given to it. Its scien- 

 tific name is Platanus occidentalis. The name means 

 "plane tree of the west", and was given to it as a mark 

 of distinction from the oriental plane tree, the scientific 

 name of which is Platanus orientalis. 



Only two of the six sycariiore trees found in the 

 world may be classed as important forest trees. They are 

 the oriental sycamore and our native sycamore of the 

 eastern United States. Scientists tell us that the syca- 

 mores are of ancient origin, and that at one time they 

 were far more abundant than now. It is their belief that 

 at one time they were quite common in Greenland and 

 in the arctic regions, and that they also existed in middle 

 Europe, where now no trace of them remains. It is also 



thought that several additional species occurred in the 

 central part of the United States in early geological 

 ages. Some of the ancient sycamores have unquestion- 

 ably become extinct, but we should be grateful that there 

 remain such magnificent trees as our common sycamores 

 found in practically every part of the eastern United 

 States, and the oriental sycamore which has no superior 

 as a street tree. 



Our native sycamore of the east is found from Maine 

 and Ontario to Nebraska and south to the gulf states 

 and west to Texas. It stands out unique among our for- 

 est trees, in that it casts its bark as well as its leaves. 

 All trees do this to a greater or less degree, for it is a 

 necessity of life that the bark yield to the pressure of 

 the growing stem on the inside. As the outer layers of 

 the bark die, they split into scales or crack into plates 

 of varying form and thickness, and finally fall oflf. In 

 the case of the shagbark hickory, silver maple, and iron- 

 wood, this process is not hidden, but the sycamore is 



BOTANICAL CHARACTERS OF BUTTONWOOD 



1. A flowering branch. 



2. A head of flowers with most of the flowers removed. 



3. A staminate flower, enlarged. 



4. A pistillate flower, enlarged. 



5. A fruiting branch with mature leaves. 



6. An achene, enlarged. 



7. A winter twig with two heads of fruit. 



8. Section of a twig showing a subpetiolar bud. 



9. Section of a twig showing a stipule, natural size. 



10. Section of a winter twig, enlarged. 



