ANALYTICAL KEY. 69 



■ II !>l l< I I se-pokoi N WOODS. 



[A lew indistinctly ring-porous woods of Group II, I), and cedar elm may seem to belong here.] 



A. Pores varying in size from large to minute; largest in spring wood, thereby- 

 giving sometimes the appearance of a ring-porous arrangement. 



1. Heavy and hard; color of heartwood (especially on longitudinal section) 

 chocolate brown (No. 116) Black walnut. 



2. Light and soft; color of heartwood light reddish brown. (No. 55) Butternut. 



B. Pores all minute aud indistinct; most numerous in spring wood, giving rise to a 

 lighter colored zone or line (especially on longitudinal section), thereby appear- 

 ing sometimes ring porous; wood hard, heartwood vinous reddish; pith rays very 

 hue, but very distinct. (See also the sometimes indistinct ring-porous cedar elm, 

 and occasionally winged elm, which are readily distinguished by the concentric 

 wavy lines of pores in the summer wood) ( No. 57) Cherry. 



C. Pores minute or indistinct, neither conspicuously larger nor more numerous in 

 the spring wood and evenly distributed. 



1. Broad pith rays present. 



a. All or most pith rays broad, numerous, and crowded, especially on tan- 

 gential sections, medium heavy and hard, difficult to split, 



(Nos. 112 and 113) Sycamore. 



b. Only part of the pith rays broad. 



a'. Broad pith rays well defined, quite numerous; wood reddish -white 

 to reddish (No. 47) Beech. 



b' . Broad pith rays not sharply defined, made up of many small rays, 

 not numerous. Stem furrowed, and therefore the periphery of sec- 

 tion, and with it the annual rings sinuous, bending in and out, and 

 the large pith rays generally limited to the furrows or concave por- 

 tions. Wood white, not reddish (No. 52) Blue beech. 



2. No broad pith rays present. 



a. Pith rays small to very small, but quite distinct. 



a'. Wood hard. 



a". Color reddish white, with dark reddish tinge in outer summer 



wood (Nos. 79-82) Maple. 



b ". Color white, without reddish tinge (No. 76) Holly. 



b'. Wood soft to very soft. 



a". Pores crowded, occupying nearly all the space between pith rays. 

 a'". Color yellowish white, often a with greenish tinge in heart- 

 wood (No. 115) Tulip poplar, 



(No. 116) Cucumber tree, 

 b" . Color of sapwood grayish, of heartwood light to dark red- 

 dish brown (No. 69) Sweet gum. 



b" . Pores not crowded, occupying not over one-third the space 

 between pith rays ; heartwood brownish \\ bite to very light brown, 



(Nos. 45 and 46) Basswood. 



b. Pith rays scarcely distinct, yet if viewed with ordinary magnifier, plainly 

 visible. 



a 1 . Pores indistinct to the naked eye. 



a". Color uniform pale yellow; pith rays not conspicuous even on 



the radial section (Nos. 53 and 54) Buckeye. 



b". Sapwood yellowish gray, heartwood grayish brown; pith rays 



conspicuous on the radial section (Nos. 67-68) Sour gum. 



b' . Pores scarcely distinct, butmostly visibleasgrayishspecks on the cross 

 section; sapwood whitish, heartwood reddish.. ..(Nos. 48-51) Birch. 



D. Pith rays not visible or else indistinct, even if viewed with magnifier. 



1. Wood very soft, white, or in shades of brown, usually with a silky luster, 



(Nos. 105-110) Cottonwood (poplar.) 



