AMERICAN ELM 



packed except in the outer part of the ring : gradually (i.e. not 

 abruptly] decreasing outwards from the pore-ring : single or paired 

 or in the late Autumn wood in. closely-packed groups of 3-15 

 pores. The larger pores 10-12 per sq. mm. : smallest (exclud- 

 ing pore-ring) 20-90 per sq. mm. 



Rays. Just visible, size 3-5, uniform : equidistant, rather 

 less than the width of a large pore apart : direct but avoiding 

 the larger pores : long, tapering : much denser than the ground- 

 tissue : 5-7 per mm. : golden-brown. 



Rings. Very clear on account of the broad zone of large 

 pores which appears light brown in the solid wood : contour 

 undulating. 



Soft-tissue. Obscure : patches accompanying and joining the 

 pores into the festoons. 



Pith. About 1-2 mm. diam., rounded or obtusely lobed : 

 white. 



Radial Section. Golden-brown spotted with dark brown. 

 Pores, prominent, deep, open, brown lines. Rays, prominent, 

 small, dark brown flakes giving the wood a spotted appearance. 

 Rings, conspicuous, as several rows of the pores are exposed in a 

 continuous band. 



Tangential Section. As the Radial, but more of the pores are 

 exposed at a time. The rays appear as just visible, fine lines 

 about i mm. high. The rings appear as conspicuously fringed 

 loops and lines. 



Type specimens from commercial sources and from trees 

 known before felling. 



No. 173. AMERICAN ELM. Ulmus americana. 



Linn. 



PLATE XII. FIG. 108. 



Natural Order. Urticaceae. 



Synonyms. U. alba. Rafin. U. floridana. Chap. U. molle- 

 folia. Marsh. 



Alternative Names. White Elm : \Yater Elm : Weisse Ulme : 

 Orme parasol : Olmo bianco (49). Red or Nova Scotia Elm 

 (12). Swamp Elm (95). Canada Elm (95). 



Sources of Supply. North America : United States and Canada. 



Physical Characters, etc. As U. Campestris (No. 171) with the 

 following variations. Recorded dry-weight 35-41 Ibs. per cu. ft. 



Grain. Moderately fine and open. Surface dull without the 

 caney appearance and feeling of the Rock Elm, but smoother. 



Bark. " Light grey and rough with longitudinal and not 

 very closely adherent ridges" (49). 



Uses, etc. " Agricultural implements, tool-handles, wagon- 



197 



