Key to Common Kind of Trees 



The following key is intended only as a guide in the identification of the more 

 common kinds of trees. It is based on prominent, distinctive characteristics 

 which can be readily observed by those who have no special training in botany. 

 Most of the terms used require no explanation. 



To use the key, decide first, by an examination of the leaf, in which of the 

 following seven sections your tree belongs; then turn to that section, and from 

 the descriptions there given determine what kind of tree it is. 



Section 

 Trees with needles or scalelike leaves, mostly evergreens, bearing cones. ... I 

 Trees with broad leaves: 

 Leaves simple — 



Alternately attached to twigs — 



With toothed edges II 



Edges neither toothed nor notched in 



Opposite on twigs — 



With toothed edges iv 



Edges neither toothed nor notched V 



Leaves compound — 



Alternately attached to twigs vi 



Opposite on twigs vii 



THE CONIFEROUS 3 TREES 



1. Trees with needle or scalelike leaves, mostly evergreen, bearing cones. 

 A. Leaves needle-shaped: 



(1) Leaves clustered — 



(a) Leaves long, from 1 to 18 inches, 2 to 5 in a cluster. Cones 



large, with many thick, woody scales (Pinus) Pine. 



(b) Leaves short (less than 2 inches long) in brushlike clusters 



of 12 to 40, falling off in late autumn or early winter. 

 Cones very small, with thin scales, remaining on tree for 

 one or more seasons (Larix) Larch. 4 



(2) Leaves single — 



{a) Leaves scattered around twigs; falling off when dry or dead. 

 Cones elongated with thin scales. Twigs roughened by 

 leaf-scars. 



(x) Leaves stiff, often sharp pointed and more or less 



foursided (Picea) Spruce. 



(y) Leaves soft, flat, rounded or notched at ends, 

 the bases abruptly contracted into threadlike 

 stems (Tsuga) Hemlock. 



2 This key and the following tree descriptions are by William H. Lamb, formerly Scientific assistant 

 in dendrology, Forest Service. 



3 Cone-bearing. 



4 The larches are peculiar in having single, scattered leaves on the new or terminal twigs produced 

 each season. These should not be mistaken for the "single" leaves borne throughout by other kinds 

 of evergreens. 



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