Sentence:  The most superficial observer of lumber knows that there is generally a considerable difference between the wood of trees belonging to different species. Sometimes it is quite small, so that lumbermen have no constitutional objection to working off short leaf for long leaf yellow pine, hemlock for white pine, <WSD>chittim</WSD> wood, or yellow cottonwood for poplar and red birch for cherry, if it can be done without detection. 
Meaning of the word marked with <WSD> tags:  The yellow cottonwood , (noshow=1).