4i6 



The Plane Tree Family 



I. SYCAMORE Platanus occidentalis Linnaeus 



This very large tree, also known as the Plane tree, Button wood. Button-ball 

 tree, and Water beech, occurs from Maine and Ontario south to Florida, and 

 westward to Nebraska and Texas, It is a frequent tree of low, rich lands, bor- 

 dering streams. Its greatest development is attained in the valleys of the 

 central States, often reaching a height of 55 meters, with a trunk diameter of 

 3.5 meters. 



The trunk is often branched from near the base into several smaller trunks, or 



is greatly reduced by the very large, promi- 

 nently outspreading branches, forming an 

 irregular, open, and very broad head; on 

 the edges of streams the trunk is often re- 

 cHning or arching far out over the water, 

 and then develops one or more tree-Hke, 

 upright branches; in the east it is usually 

 erect, and branched only above. The 

 bark of old trees is 5 to 7 cm. thick, 

 shallowly furrowed into broad ridges, which 

 are broken up into thin plates of a dark 

 brown color; on younger trunks and branches 

 the bark is quite thin and spontaneously peels 

 off into large, thin plates, exposing a smooth, 

 hght greenish gray inner layer. The twigs 

 are rather stout ; when young they are coated 

 with pale hairs, but soon become smooth, 

 Fig. 364. - Sycamore. brownish, and finally light gray. The win- 



ter buds are stout and blunt, about 10 mm. long. The leaves are orbicular in 

 outhne, 10 to 20 cm. across, 3-to 5-lobed, the lobes broad, long-pointed, and more 

 or less toothed, the teeth separated by shallow rounded sinuses; they are trun- 

 cate, heart-shaped, or rarely wedge-shaped at the base, very woolly when unfold- 

 ing, but soon become smooth, except on the veins beneath, light green and firm; 

 the stout leaf-stalk is one fourth to one third the length of the blade; the stipules 

 are conspicuous, 2 to 4 cm. long and sharp-toothed. The stalks of the flower- 

 heads are densely woolly. The fruit heads, usually solitar}-, rarely 2, are 2.5 to 4 

 cm. in diameter and light brown, hanging at the end of smooth, cord-like pe- 

 duncles 7 to 15 cm. long, persisting on the branches until the following spring. The 

 nutlets are 10 to 12 mm. long, sUghtly rounded at the top and usually capped by 

 the short persistent style. 



The wood is hard, weak, not durable, coarse-grained, light brown, having a 

 specific gravity of about 0.56. It is used to some extent for inside finishing of 

 buildings and for furniture. Butcher's blocks, rollers, and chewing-tobacco boxes 

 are largely made of it. The tree is undesirable for lawn or park planting, its young 



