TREES. 



A. USUALLY SEEN AS TREES. 



1. Evergreen : unarmed except as the simple leaves may be 



pungently pointed or toothed. 2. 

 Deciduous. 26. 



Evergreen Trees Unarmed. 



2. Foliage ("phylloid shoots") needle-like, in ter- 



minal whorls on short spurs sheathed with scales. 3. 

 Leaves not in scale-sheathed clusters. 4. 



3. Needles 1-5, angular, in a rather erect cluster. Pinus. 

 Needles numerous, flat in a spreading tuft. Sciadopitys. 



4. Leaves alternate or clustered. 5. 

 Leaves opposite, small or very narrow. 18. 



Leaves whorled, 3 at a node. Juniperus. 



Leaves alternate. 



5. Leaves small or very narrow. 6. 

 Leaves relatively large or broad. 15. 



6. Leaves 4-sided. 7. 



Leaves not 4-sided, or if so neither clustered 

 nor from raised bases. 9. 



7. Leaves often clustered on short spurs. Cedrus. 

 Leaves not clustered on spurs. 8. 



8. Leaves green, not disarticulating, 4-ranked. Cryptomeria. 

 Leaves white-lined or glaucous, disarticulating from 



angular bases. Picea. 



9. Leaves green on both sides. 10. 

 Leaves white-lined beneath, n. 



10. Fruit fleshy : leaves elongated, narrowed at base. Taxus. 

 Fruit a cone : leaves short and sharp, sessile. Sequoia. 



11. Leaves decurrent in ridges on the twigs. 12. 

 Leaves not or little decurrent. 14. 



12. Leaves mostly serrulate above : fruit a small cone. Tsuga. 

 Leaves entire. 13. 



