You’ll find a great primer on the oaks – Northern Red Oak (Quercus rubra) and White Oak (Quercus alba) – in the latest edition of Hardwood Floors Magazine. It’s relatively easy to distinguish between the two when sampling brand new boards, but trying to marry up old wood flooring with new often presents a challenge. What appears to be red oak could, in fact, be stained white oak. St. James, the author of the piece, notes that that there are 3 indicators that will help you differentiate between the two: ray height; an abundance or lack of tyloses (pore overgrowths visible on a cross section); and the characteristics (arrangement, size and shape) of the latewood vessels or pores. The article is a bit on the technical side, but it provides great information.