82 



The TJv'wq; Thh]Q:,s of the Earth unit i 



easily recogni/cd because they have 

 longer needles than any other cone 

 bearers, and their needles grow in 

 clusters. 



In the temperate /ones the conifers are 

 of great \ahie for their wood which is 

 known as softwood. Most of thcni have 

 a very stickN' sap which has a strong, 

 peculiar odor; it is called resin. The wood 

 i)unis up too fast to l)e gooil firewood, 

 but most of our lumber is sawed from 



\'h.. iu6 (above left) Red cedar. Its cone is 

 hidden within a so-called berry. (American mu- 

 seum OF NATURAL HISTORY) 



Fig. 107 (above) Pine. (Brooklyn botanic 



(IAROEN) 



Fic. loS (left) Hemlock. Hove does it differ 

 fro//; pii/c ai/d red cedar? (dickerson) 



the trunks of conifers. They are of great 

 importance, too, as a source of wood for 

 making paper. 



The true flowering plants. The true 

 flowering plants are far more numerous 

 and more varied than the cone bearers. 

 The group includes plants as different 

 as a small grass plant and an oak tree, 

 for both bear flowers and produce seeds, 

 and they resemble each other in various 

 other ways. However, there are iiupor- 



