84 ECONOMIC WOODS OF THE UNITED STATES 



usually knotty except in very small sizes; never 

 " pecky." Sp. gr. .45-53, average about .49. 

 Ray tracheitis fairly common and (1) marginal, in which 

 case they are of irregular shape or upright, or (2) con- 

 stituting low rays entirely or in alternation with ray 

 parenchyma cells. Juniper, Red or Pencil Cedar, 

 Junipcrus virginiana L. (N, C) ; Southern Red 

 Cedar, J. barbadensis L. (S).* 27 



b 3 Wood soft and more or less spongy. 



a 4 Decided contrast between seasonal growths; 

 late wood thin but hard, early wood very soft; 

 transition between the two portions of a growth 

 ring abrupt. Sp. gr. .34-. 42. Color varying 

 from various shades of brown to decidedly red- 

 dish; often streaked. Resin cells inconspicuous, 

 often zonate in widely separated growth rings. 

 Bordered pits usually in pairs near ends of tracheids in 

 early wood. Western Red Cedar, Giant Ar- 

 borvitse, Canoe Cedar, Shingle Cedar, Thuya 

 plicata Don., or T. gigantea Nutt. (P). 28 



b 4 Moderate contrast between seasonal growths; 

 late wood rather soft; transition between the 

 two portions of a growth ring gradual. Color 

 pale brown or pinkish, never very dark; little 

 contrast between heartwood and sapwood. 

 Resin cells zonate or diffuse. Bordered pits in 

 tracheids rarely paired. White Cedar Group. 



a 5 Color pale brown ; intermingling of lighter and 

 darker shades common. Resin cells rarely 

 visible with lens. Odor very mild. Wood 

 very soft and rather punky; brash. Growth 

 rings mostly narrow. Sp. gr. .28-.37, average 

 about .32. Arborvitae, Northern White Cedar, 

 T. occidentalis L. (N). 



* There are a number of western species of Juniperus but they are only of 

 local importance. Their woods resemble the eastern species but are mostly 

 harder and heavier, and the color of some of them is brown rather than deep 

 red or purple. 



