KEY TO THE PRINCIPAL TREE FAMILIES. 



A. The Evergreens, or Conifers. 

 B. Fruit, a cone. 



C. Foliage needle-like, conspicuous, spirally arrangd. 

 D. Arrangement of leaves, feu^ in sheathed bunds. 



The Pies 

 DD. Arrangement of leaves, many in unsheathe 



tufts, deciduous The Laraes 



DDD. Arrangement of leaves, solitary and scattered. 

 E. Leaves flat, blunt, pale beneath, 2-ranke( 

 on twig. 

 F. Cones erect, large; branches stiff; barl 

 smooth, with resin blisters. The frs 

 FF. Cones pendant, small ; branches sup- 

 ple ; bark rough ; leaves on minute 

 stalks. The Hemloas 



EE. Leaves 4-sided, sharp at tip, not pale be- 

 neath; standing out in all directions. 



The Sprites 

 CC. Foliage scale-like, minute, 4-ranked, close pressed 

 to twig; cones small. The White Cedas 



BB. Fruit, a blue berry; foliage spiny or scale-like, or 

 both. The Junipers, or Red Cedas 



AA. The Deciduous, Broad-leaved Trees. 

 B. Position of leaves opposite. 

 C. Leaves simple. 



D. Fruit winged, 1 -sided keys in pairs. The Mapls 

 DD. Fruit clustered berries. 



E. Flowers 4-parted; berry 2-seeded; leaves 

 not saw-toothed on margins. Tlie Dogwood 

 EE. Flowers 5-parted; berry, i -seeded; leaves 

 finely saw-toothed on margins. 



The yiburntim. 

 DDD. Fruit long, rod-like pods, with thin seeds. 



The Calalpa^ 

 CC. Leaves compound. 



D. Fruit slender, winged darts in thick clusters; 

 leaflets set along central leaf stem. The Ashet 

 DD. Fruit large nuts in leathery husks; leaflets 

 clustered on end of leaf stalk. The Buckeyes 

 BB. Position of leaves alternate. 



14 



