Q: I am new to this business and cannot get good answers about poplar lumber. I hear about yellow poplar in our N.C. operation and aspen poplar when I visit New England, but they are not the same wood to my eye. Can you take a moment to explain?

A: You have asked for clarification about an issue that can even confuse those people who are quite a bit more experienced. In brief, there is a genus called Populus . Within that genus are at least eight North American species that we see on the commercial lumber market, including trembling or quaking aspen or popple ( P. tremuloides ), bigtooth aspen or popple ( P. grandidentata ), balsam poplar, black poplar or balm of Gilead ( P. balsamifera ), Eastern cottonwood ( P. deltoids ), and black or California cottonwood ( P. trichocarpa ). (These species have other local names too; I have chosen the most common here.) In Europe and other continents, they also have species that are in the Populus genus.

It would not be uncommon to hear all of these, from time to time, except for Eastern cottonwood, called poplar, because they are in the Populus genus. However, the properties and color vary widely at times when comparing the various species. (Note that the genus name is always capitalized, and both species and genus are italicized, by convention.)

The National Hardwood Lumber Association calls quaking and bigtooth poplar by the name of aspen or popple in the grading rules. They do not use the name poplar at all for these two species. Incidentally, most aspen will be quaking, as bigtooth is not too plentiful.

Further, they use cottonwood for the cottonwood species.

This means that balm of Gilead is not clearly included in either grouping; in terms of processing, it would be closer to cottonwood however. In my experience, I have seen balm of Gilead lumber included with aspen (it is called balsam poplar then), but there is a big difference in color and drying properties, so this is probably not correct or desired.

Finally, the NHLA uses the term poplar for American tulipwood, which we know as yellow-poplar or tulip poplar in most cases. The Latin name for this tree is Liriodendron tulipifera . Its leaves are shaped like a tulip flower (if you use a small bit of imagination); hence the use of "tulip" in the species name. Note that it is not in the Populus genus. Nevertheless, within the trade, it is often called just poplar. Yellow-poplar is a much denser, stronger and stiffer wood than the species in the Populus genus. Oftentimes, yellow-poplar has a greenish hue to it, compared to the much whiter color of the Populus species woods.