SPECIES FOR STREET-PLANTING 47 



close around it like the ribs of an umbrella. When the ripe 

 fruit is released the hairs open up and form a little para- 

 chute that keeps the seed suspended in the air for a consid- 

 erable period of time, and enables the wind to carry it far 

 away from the parent tree. 



The oriental plane is not troubled by many insect pests. 

 The tussock moth and the fall web-worm sometimes attack 

 it, but they never cause serious injury. The sycamore is 

 subject to a fungous disease that attacks the young leaves as 

 they come out of the bud, causing them to turn brown and 

 shrivel up. The European species is less subject to this 

 disease. 



Tulip-Tree (Liriodendron tulipifera Linn.). — The tulip- 

 tree is one of the largest and most beautiful of our native 

 trees. It belongs to the magnolia family and, like all the 

 members of that group, it has large, brilliant flowers. 

 Their color is greenish-yellow, with dashes of red and orange, 

 and their resemblance to a tulip is marked. They open in 

 May, shortly after the development of the leaves, and are 

 borne on stout stems that keep them erect. 



The flowers of the tulip are complete. The fruit of the 

 tulip is a cone, two or three inches long, composed of thin, 

 narrow scales attached to a common axis. These scales are 

 each a seed surrounded by a thin wing. The fruit ripens 

 during October, and, beginning at the top of each cone, one 

 by one the seeds become detached from the central axis, 

 and by the aid of the wind each seed is carried some dis- 

 tance from the tree. 



The leaves of the tulip are unique in shape, the 

 "chopped off" ends giving them an individuality of their 

 own. When fully developed the leaves have a tremulous 

 motion, resembling those of the poplars, and for that reason 



