90 ECONOMIC WOODS OP THE UNITED STATES 



pact. Fairly easy to split. Rock or Hickory 

 Elm. U. racemosa Thomas (C, N). 



b* Bands of small pores numerous; wider than 

 intervening spaces. Wood moderately hard. 

 Difficult to split. 



Winged Elm. U. alata Michx. (S, C). 



b' Growth rings indistinct. Bands of small pores 

 broad, very wavy, and branched. Wood hard. 

 Difficult to split. 



Cedar Elm. U. crassifolia Nutt. (S). 



3 Pores in late wood small. dis1;,ribnt^ d-aill£bi. in groups 

 mostly short, broken (occasionally continuousj more a 



^ ,. m 



Wngential Imes. Ravs fairly uniform, fine to minute . Wood 

 parenchyma around pores or extending wing-like from pores 

 in late wood, often uniting them into irregular tangential 

 lines. Outer limit of growth ring consists chiefly or exclu- 

 sively of wood parenchyma. 



a Por es in early wood very small , indistinct, rather widely 

 separated m a smgle row. Wood very light, soft , weak , 

 difficult to cut smoothly across the grain. 



Water Ash. Fraxinus caroliniana Mill. (S). 



b Pores in earlv wood large, conspicuous, usually in a rather 

 broad zone 3-10, rarely 1-2, rows wide. 



a^ Rays narrow (1-5 cells), inconspicuous; almost invisible 

 on cross section to unaided eye. _Color pale or dull 

 brown to nearlv white : not very deep or striking. 



a^ Odorless and tasteless. Medium to very heavv and 

 hard. Pores in late wood isolated, or m groups of 2-3, 

 or "united by wood parenchyma into mostly short 

 tangential lines, especially in outer portion of growth 

 ring. Color brown to white, sometimes with reddish 

 tinge to late wood. Sapwood very thick, white. 

 Demarcation in color between heartwood and sap- 

 wood not clear. Rays homogeneous. Ash. 



a' Pores in late wood usually joined tangentially by 

 wood parenchyma. Wood very hard and strong. 



a* Pores in early wood in rather broad zone; 

 numerous. 



