Within the massive Quercus genus, oak species are subdivided into a number of sections, though all commercially harvested New World oaks can be placed into one of two categories: red oak, or white oak. This division is based on the morphology of the trees themselves—for instance, red oaks have pointed lobes on the leaves, while white oaks have rounded lobes. While there is one specific wood species (Quercus alba) that’s commonly considered the “white oak,” and there is one specific species (Quercus rubra) that’s considered the “red oak,” when you buy oak lumber within North America, oftentimes you will not actually be buying these two exact species, but instead you may be buying one of the oaks contained within the two broad red and white groupings. Basically, you’re buying characteristics found in an oak group, and not necessarily an exact species. For the rest of this article, I’ll be referring to red oaks and white oaks (plural) as two different groups of trees, and not simply as individual species. At a casual glance, unfinished oak lumber will generally be light brown, either with a slight reddish cast (usually red oak), or a subtle olive-colored cast (white oak). However, there are abnormally light or dark outliers and pieces that are ambiguously colored, making separation based on color alone unreliable—this is especially true if the wood is finished and/or stained.