GENERAL CLASSIFICATION OF THE WOOD 

 OF TREES INCLUDED IN THE MANUAL. 



A. Wood without annual rinses, but with scattered vas- 

 cular bundles. Monocotylae. 



(No trees in our region). 



B. ,Woo(l in a growini^- cylinder, showing annual rings, with 



a central i)ith. 



T. Wood non-porous, the cells not visible or con- 

 spicuous in cross section even with a hand lens, 

 there being no wood vessels ; annual rings dis- 

 tinct b}^ denser dark-colored bands of late w^ood. 

 Ginkgoeae and Coniferae. 



1. Resin-ducts present in cross section. 



a. Without distinct heartwood. Picea. 



b. v^ith distinct heartwood. Larix, Pinus. 



2. Resin-ducts not present in the wood. 



a. Resin-ducts in the pith. Ginkgo. 



b. Pith without resin-ducts. 



(a) Wrthout distinct heartwood. Abies, 

 Tsuga. 



(b) With distinct heartwood, either of a 

 different color or of a deeper shade 

 than the sapwood. 



((a)) Without a sharp demarcation in 

 color between the heartwood and 

 sapwood, the one fading gradually 

 into the other. Taxodium, Chamae- 

 cyparis, Thuja. 



((h)) With a clear demarcation in color 

 between the heartwood and sapwood. 

 Libocedrus, Juniperus. 



IT. Wood porous; the pores, or true wood vessels, be- 

 ing visible in cross section' with a hand lens or to 

 the naked eye. Dicotylae. 



1. Wood diffuse-porous; pores lunncrous and 

 usually not plainly visible in cross section 

 (138) 



